Conduit gripping device having retaining structure for conduit fitting

ABSTRACT

A fitting subassembly includes a threaded fitting nut that can be joined with a threaded fitting body to form a fitting assembly. The fitting nut includes a radial drive surface and an interior wall defining a socket. A back ferrule is disposed entirely in the socket and includes a driven surface adjacent to the drive surface, and a front ferrule is at least partially disposed in the socket. A retaining member retains the front and back ferrules with the fitting nut as a subassembly prior to the fitting nut being assembled with a threaded fitting body. The retaining member applies a retaining force that is limited to permit removal of the front ferrule and the back ferrule from the fitting nut by exposure to a force applying environment.

RELATED APPLICATIONS

This application is a continuation application of U.S. Ser. No.15/172,305, filed Jun. 3, 2016, entitled CONDUIT GRIPPING DEVICE HAVINGRETAINING STRUCTURE FOR CONDUIT FITTING which is a continuationapplication of U.S. Ser. No. 14/556,322, filed Dec. 1, 2014, entitledCONDUIT GRIPPING DEVICE HAVING RETAINING STRUCTURE FOR CONDUIT FITTINGwhich is a continuation application of U.S. Ser. No. 13/009,325, filedJan. 19, 2011, entitled CONDUIT GRIPPING DEVICE HAVING RETAININGSTRUCTURE FOR CONDUIT FITTING, now U.S. Pat. No. 8,931,810 which claimsthe benefit of the following five United States provisional patentapplications: U.S. Provisional Patent Application Ser. No. 61/297,066,entitled FITTING COMPONENT WITH CONDUIT GRIPPING DEVICE RETAININGSTRUCTURE and filed Jan. 21, 2010, U.S. Provisional Patent ApplicationSer. No. 61/331,035, entitled CONDUIT GRIPPING DEVICE HAVING RETAININGSTRUCTURE FOR CONDUIT FITTING and filed May 4, 2010, U.S. ProvisionalPatent Application Ser. No. 61/331,025, entitled CONDUIT FITTING WITHCONDUIT GRIPPING DEVICE RETAINING RING and filed May 4, 2010, U.S.Provisional Patent Application Ser. No. 61/331,028, entitled FITTINGCOMPONENT WITH CONDUIT GRIPPING DEVICE RETAINING CLIP and filed May 4,2010, and U.S. Provisional Patent Application Ser. No. 61/331,032,entitled CONDUIT FITTING WITH CONDUIT GRIPPING DEVICE RETAININGSTRUCTURE and filed May 4, 2010. The entire disclosures of all of theabove applications are fully incorporated herein by reference

TECHNICAL FIELD OF THE INVENTIONS

The present disclosure relates to fittings for making mechanicallyattached connections between a conduit and another fluid component, forcontaining liquid or gas fluids. More particularly, the disclosurerelates to fittings for tube and pipe conduits that use one or moreconduit gripping devices, such as for example, one or more ferrules.

SUMMARY OF THE DISCLOSURE

In accordance with an embodiment of one or more of the inventionspresented in this disclosure, a fitting subassembly includes a threadedfitting nut that can be joined with a threaded fitting body to form afitting assembly. The fitting nut includes a radial drive surface and aninterior wall defining a socket. A back ferrule is disposed entirely inthe socket and includes a driven surface adjacent to the drive surface,and a front ferrule is at least partially disposed in the socket. Aretaining member retains the front and back ferrules with the fittingnut as a subassembly prior to the fitting nut being assembled with athreaded fitting body. The retaining member applies a retaining forcethat is limited to permit removal of the front ferrule and the backferrule from the fitting nut by exposure to a force applyingenvironment.

In accordance with another embodiment of one or more of the inventionspresented in this disclosure, a fitting assembly for conduits includes athreaded first fitting component to be assembled with a threaded secondfitting component to provide an interior volume, a front ferrule and aback ferrule both disposed entirely in the interior volume, with thesecond fitting component including a drive surface that engages a backwall of the back ferrule when the fitting assembly is pulled-up. Aretaining member retains the front and back ferrules with the secondfitting component as a subassembly prior to the first fitting componentbeing assembled with the second fitting component. The retaining memberapplies a retaining force that permits removal of the front ferrule andthe back ferrule from the second fitting component by exposure to aforce applying environment.

In accordance with another embodiment of one or more of the inventionspresented in this disclosure, a fitting subassembly includes a firstfitting component that can be joined to a second fitting component tomake a threaded fitting assembly, with the first fitting componentincluding an interior wall defining a socket. At least one conduitgripping device is disposed within the socket, and a retaining member,separate from and assembled with the first fitting component, retainsthe at least one conduit gripping device with the first fittingcomponent. The retaining member is movable with respect to the firstfitting component from a first position in which the at least oneconduit gripping device is retained with the first fitting component, toa second position in which the at least one conduit gripping devicebecomes separable from the first fitting component.

In accordance with an embodiment of one or more of the inventionspresented in this disclosure, at least one conduit gripping device and afirst coupling or fitting component are retained together as adiscontinuous unit or cartridge prior to the unit being assembled with asecond coupling or fitting component to form a complete fittingassembly. In another embodiment, a retaining structure may be providedby which one or more conduit gripping devices and a first coupling orfitting component are retained together as a discontinuous unit orcartridge prior to being assembled with a second fitting component. In amore specific embodiment, a retaining structure may be provided thatretains at least two discrete conduit gripping devices with a discretefitting component as a discontinuous unit or cartridge, wherein theretaining structure comprises structural features associated with one ormore of the conduit gripping devices and the fitting component. Forexample, in one embodiment, a front ferrule comprises an extension, forexample a skirt or tang, that engages an interior surface of a fittingcomponent such as, for example, a nut.

In another embodiment, a conduit gripping device or ferrule may beprovided with a retaining structure in the form of a flange or otherradial extension that in a first or retaining position retains theferrule or a ferrule set with a retaining fitting component as adiscontinuous unit or cartridge prior to the unit being assembled with asecond coupling or fitting component to form a complete fittingassembly. In another embodiment, such a flange bends or deflects into asecond or release position during a partial or complete pull-up.

Additional features may include a retaining structure that does notadversely interfere with initial pull-up or subsequent remakes of thefitting assembly, a retaining structure that uses metal components sothat the fitting assembly comprises all metal parts, and a retainingstructure that may loosely retain the one or more conduit grippingdevices so as to facilitate assembly to a finger tight position and apulled-up position.

In another embodiment, for fitting assemblies that use two or moreconduit gripping devices or two or more parts of the conduit grippingdevice, a cartridge design is provided that holds the conduit grippingdevices and related parts, if any, together as a separate discrete unitprior to assembly with the retaining fitting component. In an exemplaryembodiment, two ferrules are held together as a cartridge ferrule set inthe form of a discrete unit prior to assembly with a retaining fittingcomponent.

In another embodiment, a retaining structure may be provided thatcomprises a bendable or flexible member that extends from an interiorwall of a socket of the retaining fitting component to retain a conduitgripping device therewith. In still a further embodiment, the matingfitting component contacts the retaining structure and may plasticallydeforms the member to allow the retaining fitting component to beseparable from the one or more conduit gripping devices.

In another embodiment, a retaining structure may be provided thatcomprises a retaining member that is retained in a recess in an interiorwall of the retaining fitting component to retain a conduit grippingdevice. In still a further embodiment, the retaining member may comprisea flexible ring or other generally annular device that is radiallydimensioned to interfere or contact a surface of a conduit grippingdevice to retain the conduit gripping device with the retaining fittingcomponent as a cartridge or subassembly. In another exemplaryembodiment, the retaining member may comprise an o-ring or otherradially flexible device that has a first radial dimension to retain aconduit gripping device, and that may radially expand to allow theretaining fitting component to be axially separated from the matingfitting component and the conduit gripping device.

In another embodiment, a retaining structure may be provided thatcomprises a retaining member that cooperates with an interior wall ofthe retaining fitting component to retain a conduit gripping devicetherewith. In still a further embodiment, the retaining member may bedisplaced axially, or radially, or both relative to the retainingfitting component between two positions to retain or release the conduitgripping device relative to the retaining structure. In anotherembodiment, the mating fitting component contacts the retaining memberat a first position and the retaining member moves relative to theretaining fitting component to a second position to allow the retainingmember to be released or separable from the one or more conduit grippingdevices. In an exemplary embodiment, the retaining member comprises ano-ring, snap ring or any other generally annular or separate member thatcan be repositioned by the mating fitting component during pull-up.

In another embodiment, a retaining structure may be provided thatcomprises a retaining member that holds at least one conduit grippingdevice with the retaining fitting component, the retaining memberreleasing the at least one conduit gripping device when the at least oneconduit gripping device deforms during at least a partial pull-up of thefitting onto a conduit. In an exemplary embodiment, the retaining membercomprises a hook or clip-like device that can attach to the retainingfitting component and a conduit gripping device, with the clip-likedevice and the conduit gripping device being separable or released fromeach other when the conduit gripping device deforms during pull-up. Theinventions herein further include but are not limited to a preassemblyof a retaining fitting component, a conduit gripping device and a hookor clip-like retaining member; and a preassembly of a ferrule retainerfor a ferrule with a retaining fitting component wherein the ferruleretainer comprises a hook or clip-like device that can connect theferrule and the retaining fitting component together as a cartridge. Inanother embodiment, a conduit gripping device may be welded or otherwiseattached to a retaining fitting component, for example, with adhesive orsimilar materials, to form a cartridge.

These and other aspects and advantages of the inventions describedherein will be readily appreciated and understood by those skilled inthe art in view of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an embodiment of a conduit fitting cartridge, subassembly orpreassembly illustrating one embodiment of one or more of the inventionsherein, shown in longitudinal cross-section.

FIG. 2 is an embodiment of a conduit fitting assembly using thesubassembly of FIG. 1, with the fitting assembly illustrated in a fingertight position.

FIG. 3 is an enlarged view of the circled region A of FIG. 2.

FIGS. 4A-4D illustrate Finite Element Analysis (FEA) simulations ofanother embodiment of one or more of the inventions herein during anassembly process, shown in half-longitudinal cross-section.

FIGS. 5A-5D illustrate FEA simulations of the embodiment of FIGS. 4A-4Eduring a complete pull-up of the fitting, shown in half-longitudinalcross-section.

FIGS. 5E and 5F illustrate FEA simulations of the embodiment of FIGS.4A-4D during partial disassembly of the fitting after a complete pull-upof the fitting as in FIGS. 5A-5D, shown in half-longitudinalcross-section.

FIG. 6 is another embodiment of a fitting having a discontinuouscartridge of a ferrule retained with a fitting component.

FIGS. 7A and 7B illustrate FEA simulations of another embodiment of afitting having a subassembly of a ferrule retained with a fittingcomponent, in a finger tight and pulled-up position respectively, inhalf-longitudinal cross-section.

FIGS. 8A and 8B illustrate another embodiment of a fitting having asubassembly of a ferrule retained with a fitting component, for a malethreaded nut, illustrated in half-longitudinal cross-section for afinger-tight position and a pulled-up position respectively.

FIGS. 9A and 9B illustrate another embodiment of a fitting having adiscontinuous cartridge of one or more conduit gripping devices retainedwith a fitting component, in a finger tight position, with FIG. 9B beingan enlarged view of the circled portion of FIG. 9A.

FIG. 10 illustrates another embodiment of a cartridge assembly using aferrule cartridge concept, shown in half longitudinal cross section in afinger-tight position.

FIG. 11 illustrates the embodiment of FIG. 10 in a pulled-up position.

FIG. 12 another embodiment of a conduit fitting cartridge, subassemblyor preassembly illustrating one or more of the inventions herein, shownin longitudinal cross-section.

FIG. 13 is an enlarged view of the conduit fitting cartridge of FIG. 12.

FIGS. 14-16 are a side elevation, back (outboard) elevation andperspective view respectively of a conduit gripping device with aretaining flange as may be used with the embodiment of FIG. 12.

FIG. 17 illustrates in a stylized manner the embodiment of FIGS. 12 and13 in a pulled up condition.

FIG. 18 is another embodiment of a conduit fitting cartridge,subassembly or preassembly illustrating one embodiment of one or more ofthe inventions herein, shown in longitudinal cross-section.

FIG. 19 illustrates an embodiment of a fitting assembly using thesubassembly of FIG. 1, shown in a finger-tight position.

FIG. 20 illustrates the embodiment of FIG. 19 for the nut and bodyfitting components in an assembled position of a partial or completepull-up.

FIG. 21 illustrates another embodiment using a single conduit grippingdevice.

FIG. 22 illustrates another embodiment of a conduit fitting cartridge.

FIG. 23 is an embodiment of a conduit fitting cartridge, subassembly orpreassembly illustrating one embodiment of one or more of the inventionsherein, shown in longitudinal half cross-section and joined to a secondfitting component in a finger-tight position;

FIG. 24 is another embodiment of the fitting cartridge of FIG. 23 toinclude a ferrule cartridge assembly concept;

FIG. 25 illustrates another embodiment of a fitting cartridge, shown inlongitudinal cross-section and joined with a second fitting component ina finger-tight position;

FIG. 26 illustrates an enlarged view of the circled region of FIG. 25;

FIGS. 27A and 27B illustrate a plan view of two examples of a retainingring that may be used in the embodiment of FIG. 25;

FIG. 28 illustrates the assembly of FIGS. 25 and 26 in a pulled-upposition;

FIG. 29 illustrates another embodiment using a cartridge nut concept asin FIG. 25 in combination with a ferrule cartridge assembly concept;

FIGS. 30-32 illustrate another embodiment of a cartridge nut using aretaining ring for a ferrule, in cutaway, elevation and perspectiveviews respectively.

FIG. 33 is another embodiment of a conduit fitting cartridge,subassembly or preassembly illustrating one embodiment of one or more ofthe inventions herein, shown in longitudinal cross-section and joined toa second fitting component in a finger tight position.

FIG. 34 is an enlarged view of the circled region A in FIG. 33.

FIG. 35 illustrates the embodiment of FIG. 34 with the fittingcomponents in an assembled position of a partial or complete pull-up.

FIG. 36 illustrates another embodiment of a conduit fitting cartridgeusing a ferrule cartridge arrangement, shown in half-longitudinalcross-section and in a finger-tight position.

FIG. 37 illustrates the embodiment of FIG. 36 in a pulled-up position.

FIG. 38 illustrates another embodiment of a cartridge nut concept in thefinger-tight position and shown in longitudinal cross-section.

FIG. 39 is an enlarged view of the circled region of FIG. 38.

FIG. 40 illustrates the embodiment of FIGS. 38 and 39 in a pulled-upcondition.

FIG. 41 illustrates another embodiment of a cartridge nut concept in thefinger-tight position and shown in longitudinal cross-section.

FIG. 42 illustrates the embodiment of FIG. 41 in a pulled-up condition.

FIG. 43 is an embodiment of a conduit fitting cartridge, subassembly orpreassembly illustrating one embodiment of one or more of the inventionsherein, shown in longitudinal cross-section and joined to a secondfitting component in a finger tight position, with the conduit omittedfor clarity;

FIG. 44 is an enlarged view of the circled region A in FIG. 43;

FIG. 45 illustrates the embodiment of FIG. 44 with the fittingcomponents in an assembled position of a partial or complete pull-uponto a conduit end;

FIG. 46 illustrates another embodiment of a conduit fitting cartridge,subassembly or preassembly illustrating one embodiment of one or more ofthe inventions herein, shown in longitudinal cross-section and joined toa second fitting component in a finger tight position, with the conduitomitted for clarity;

FIG. 47 is an enlarged view of the circled region B in FIG. 46;

FIG. 48 illustrates the embodiment of FIG. 46 with the fittingcomponents in an assembled position of a partial or complete pull-uponto a conduit end;

FIG. 49 illustrates an embodiment of a conduit fitting cartridge usingwelded parts, for example, tack welded.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Although the exemplary embodiments herein are presented in the contextof a stainless steel tube fitting, the inventions herein are not limitedto such applications, and will find use with many different conduitssuch as tube and pipe as well as different materials other than 316stainless steel, including metals and non-metals for either the conduit,the gripping devices or the fitting components or any combinationthereof. The inventions may also be used for liquid or gas fluidsystems. While the inventions herein are illustrated with respect toparticular designs of the conduit gripping devices and fittingcomponents, the inventions are not limited to use with such designs, andwill find application in many different fitting designs that use one ormore conduit gripping devices. We use the term “conventional” to referto commercially available or later developed parts or parts that areotherwise commonly known, used or that those of ordinary skill in theart would be familiar with in general, as distinguished from parts thatmay be modified in accordance with teachings herein. We use the term“ferrule set” to refer to a combination of conduit gripping devices withor without other parts that form the means by which conduit grip andseal are achieved. Although not necessary with all fitting designs, itis common that a ferrule set comprises two ferrules that are purposelymatched to each other and to the fitting components, for example, basedon material, manufacturer, interrelated design and geometry features andso on. In some fittings, in addition to the conduit gripping devicesthere may be one or more additional parts, for example seals. Therefore,the term “ferrule set” may also include in some embodiments thecombination of one or more conduit gripping devices with one or moreother parts by which the ferrule set effects conduit grip and seal aftera complete pull-up. The inventions may be used with tube or pipe, so weuse the term “conduit” to include tube or pipe or both. We generally usethe term “fitting assembly” or “fitting” interchangeably as a shorthandreference to an assembly of typically first and second fittingcomponents along with one or more conduit gripping devices. The conceptof a “fitting assembly” thus may include assembly of the parts onto aconduit, either in a finger-tight position, a partial pull-up positionor complete pull-up position; but the term “fitting assembly” is alsointended to include an assembly of parts together without a conduit, forexample for shipping or handling, as well as the constituent partsthemselves even if not assembled together. Fittings typically includetwo fitting components that are joined together, and one or moregripping devices, however, the inventions herein may be used withfittings that include additional pieces and parts. For example, a unionfitting may include a body and two nuts. We also use the term “fittingremake” and derivative terms herein to refer to a fitting assembly thathas been at least once tightened or completely pulled-up, loosened, andthen re-tightened to another completely pulled-up position. Remakes maybe done with the same fitting assembly parts (e.g. nut, body, ferrules),for example, or may involve the replacement of one of more of the partsof the fitting assembly. Reference herein to “outboard” and “inboard”are for convenience and simply refer to whether a direction is towardsthe center of a fitting (inboard) or away from the center (outboard). Inthe drawings, various gaps and spaces between parts (for example, gapsbetween the ferrules and the conduit in a finger-tight position) may besomewhat exaggerated for clarity or due to scale of the drawings.

A significant feature of some of the inventions herein is the provisionof a retaining structure by which one or more conduit gripping devicesare retained with a fitting component, also referred to herein as aretaining fitting component, prior to assembly of the fitting componentwith a mating fitting component. By “cartridge” we mean a group of partsretained together as a discontinuous unit, subassembly or preassembly.We therefore use the terms cartridge, unit, subassembly and preassemblysynonymously herein in the context of a discontinuous structure. We alsouse the term “cartridge nut” or “conduit fitting cartridge” herein torefer to such a cartridge, unit or subassembly in which one or moreconduit gripping devices are retained with a fitting component such as afemale nut, for example. We also use the term “ferrule cartridge” or“conduit gripping device cartridge” to refer to a unit or subassemblymade up of at least one ferrule or conduit gripping device with at leastone other part held together as a discrete unit. In particular, a“ferrule cartridge” includes two or more ferrules held together as adiscrete unit or subassembly, and may include additional parts, forexample, seals. In the exemplary embodiments herein, the cartridgeincludes one or more ferrules retained with a fitting component, such asa female threaded nut. Therefore, the exemplary embodiments herein maybe referred to as a cartridge nut design, however in alternativeembodiments, a “cartridge nut” may include a male threaded cartridge nutdesign or a cartridge body design.

While various inventive aspects, concepts and features of the inventionsmay be described and illustrated herein as embodied in combination inthe exemplary embodiments, these various aspects, concepts and featuresmay be used in many alternative embodiments, either individually or invarious combinations and sub-combinations thereof. Unless expresslyexcluded herein all such combinations and sub-combinations are intendedto be within the scope of the present inventions. Still further, whilevarious alternative embodiments as to the various aspects, concepts andfeatures of the inventions—such as alternative materials, structures,configurations, methods, circuits, devices and components, software,hardware, control logic, alternatives as to form, fit and function, andso on—may be described herein, such descriptions are not intended to bea complete or exhaustive list of available alternative embodiments,whether presently known or later developed. Those skilled in the art mayreadily adopt one or more of the inventive aspects, concepts or featuresinto additional embodiments and uses within the scope of the presentinventions even if such embodiments are not expressly disclosed herein.Additionally, even though some features, concepts or aspects of theinventions may be described herein as being a preferred arrangement ormethod, such description is not intended to suggest that such feature isrequired or necessary unless expressly so stated. Still further,exemplary or representative values and ranges may be included to assistin understanding the present disclosure, however, such values and rangesare not to be construed in a limiting sense and are intended to becritical values or ranges only if so expressly stated. Moreover, whilevarious aspects, features and concepts may be expressly identifiedherein as being inventive or forming part of an invention, suchidentification is not intended to be exclusive, but rather there may beinventive aspects, concepts and features that are fully described hereinwithout being expressly identified as such or as part of a specificinvention, the inventions instead being set forth in the appendedclaims. Descriptions of exemplary methods or processes are not limitedto inclusion of all steps as being required in all cases, nor is theorder that the steps are presented to be construed as required ornecessary unless expressly so stated.

With reference to FIGS. 1 and 2, a first embodiment of one or more ofthe inventions is presented. Note that in many of the drawings herein,for example FIG. 3, the fittings are illustrated in half longitudinalcross-section, it being understood by those skilled in the art that thefitting components are in practice annular parts about a longitudinalcenterline axis X. All references herein to “radial” and “axial” arereferenced to the X axis except as otherwise noted. Also, all referencesherein to angles are referenced to the X axis except as may be otherwisenoted.

In this disclosure unless otherwise noted, a fitting assembly 10 mayinclude a first coupling or fitting component 12 and a second couplingor fitting component 14. These parts are commonly known in the art as abody and nut respectively, wherein the body 12 receives a conduit 18 endshown in phantom in FIG. 2 (also see FIG. 5A for example), and the nut14 may be joined to the body 12 during make up of the fitting. Althoughwe use the common terms of body and nut herein as a convenience, thoseskilled in the art will appreciate that the inventions are not limitedto applications wherein such terminology may be used to describe theparts. The body 12 may be a stand-alone component as illustrated or maybe integral with or integrated or assembled into another component orassembly such as, for example, a valve, a tank or other flow device orfluid containment device. The body 12 may have many differentconfigurations, for example, a union, a tee, an elbow and so on to namea few that are well known in the art. Although the body 12 and nut 14are illustrated as being threadably joined together by a threadedconnection 16, threaded connections are not required in all uses. Forexample, some fittings have parts that are clamped together. Fittingsare also commonly referred to in the art as male fittings or femalefittings, with the distinction being that for a male fitting the malebody 12 includes an externally threaded portion 16 a and the female nut14 includes an internally threaded portion 16 b. For a female fitting,the male nut 12 includes an externally threaded portion 16 a and thefemale body 14 includes an internally threaded portion 16 b. FIGS. 1-3illustrate a male fitting assembly embodiment, for example, and FIG. 8A,for example, illustrates a female fitting assembly embodiment. Many ofthe exemplary embodiments herein illustrate a male fitting assemblyembodiment, for example, but the inventions herein also may beconveniently adapted for use with a female fitting assembly. When thefitting components, such as a body and nut for example, are joined theyform a generally enclosed interior space or volume for the conduitgripping devices, other optional seal components, a portions or all of aretaining feature for the cartridge nut concepts in the interior spaceor volume.

The fitting assembly 10 may be used to form a fluid tight connectionbetween an end portion 18 a of a conduit 18 and the body 12 using one ormore conduit gripping devices, which in the exemplary embodiments hereinmay be realized in the form of one or more ferrules. However, conduitgripping devices other than those that may be understood in the art as‘ferrules’ may also be used with the inventions herein. The conduit end18 a typically bottoms against a radial shoulder 19 (FIG. 2) that ispart of the body 12, as is well known. The body 12 includes a taperedcamming surface 20 that engages the front portion 22 of a first or frontconduit gripping device or ferrule 24. The front ferrule 24 includes atapered camming surface 26 (see FIG. 3) at its back end that engages afront portion 28 of a second or back conduit gripping device or ferrule30. The back ferrule 30 includes a driven surface 32 that engages adrive surface 34 of the female nut 14. The back ferrule front portion 28may optionally include a radially extending crown 36. The front and backferrules include cylindrical interior walls 37, 39 that are closelyreceived over the outer surface 38 of the conduit 18. The back ferrulemay optionally include one or more radial recesses 39 a. Although theexemplary embodiments herein illustrate fitting assemblies that use aconduit gripping device or ferrule set having two conduit grippingdevices or ferrules, the inventions will readily find application tofittings that may use only a single conduit gripping device, as well asfittings that may use ferrule sets having more than two conduit grippingdevices, or additional parts other than just ferrules or conduitgripping devices, for example, additional seals.

It is important to note that the exemplary geometric shapes,configurations and designs of the fitting coupling components 12, 14,and the conduit gripping devices 24, 30 are a matter of design choiceand will depend in great measure on the materials used, and the designand performance criteria expected of the fitting. Many differentcoupling components and conduit gripping device designs are known in theart and may be designed in the future. The present disclosure and theinventions described herein and illustrated in the context of exemplaryembodiments are directed to structure and method of retaining at leastone conduit gripping device with one or a first of the fittingcomponents as a discontinuous subassembly or cartridge which canthereafter be joined with another or second fitting component to form afitting assembly.

The term “complete pull-up” and derivative forms as used herein refersto joining the fitting components together so as to cause the one ormore conduit gripping devices to deform, usually but not necessarilyplastically deform, to create a fluid tight seal and grip of the fittingassembly 10 on the conduit 18. A “partial pull-up” and derivative termsas used herein refers to a partial but sufficient tightening of the maleand female fitting components together so as to cause the conduitgripping device or devices to deform so as to be radially compressedagainst and thus attached to the conduit, but not necessarily havingcreated a fluid tight connection or the required conduit grip that isachieved after a complete pull-up. The term “partial pull-up” thus mayalso be understood to include what is often referred to in the art aspre-swaging wherein a swaging tool is used to deform the ferrules ontothe conduit sufficiently so that the ferrules and the nut are retainedon the conduit prior to being mated with the second fitting component toform a complete fitting assembly. A finger tight position or conditionrefers to the fitting components and conduit gripping devices beingloosely assembled onto the conduit but without any significanttightening of the male and female fitting components together, usuallytypified by the conduit gripping device or devices not undergoingplastic deformation.

We use the term “discontinuous” to describe the conjoined nature of thecartridge or preassembly in the sense that the one or more conduitgripping devices and the fitting component (also referred to herein asthe retaining fitting component), for example a female threaded nut inthe FIG. 1 embodiment, are manufactured as separate and discretecomponents and remain separate and discrete components, although inaccordance with the inventions herein these components may be retainedtogether as a discrete cartridge, subassembly or preassembly, andfurther wherein after final assembly or even a complete pull-up theparts remain discrete and may be disassembled into their constituentdiscrete parts if so desired. The terms “discontinuous” or “conjoined”are used herein to distinguish from fitting designs in which a conduitgripping device is attached to or made integral with a fittingcomponent, wherein the conduit gripping device may remain integral ormay in some designs break off or detach from the fitting componentduring complete or partial pull-up. In a discontinuous type structure,as that terminology is used in this disclosure, the one or more conduitgripping devices may optionally release or become separable from theretaining fitting component during either partial or complete pull-upwithout requiring a fracture, shear or other separation of material oradhesive. The terms “discontinuous” or “conjoined” are further intendedto include broadly the idea that the one or more conduit grippingdevices may be loosely or alternatively snugly retained with theretaining fitting component.

FIG. 2 illustrates the fitting assembly 10 in a finger-tight condition,meaning that the various parts 12, 14, 24 and 30 have been assembledonto the conduit 18 (illustrated in phantom for clarity) but are looselyassembled or slightly tightened or snugged up a bit by manually joiningthe nut 14 and body 12 together. Fittings are commonly pulled-up to acomplete pulled-up position by counting complete and partial turns ofthe nut 14 relative to the body 12 from the finger-tight position. Thepresent inventions, however, may be used with fitting designs thatalternatively may be pulled-up by torque.

In order to effect complete conduit grip and seal, the nut and body aretightened together—commonly known in the art as pull-up or pulling upthe fitting and derivative terms—such that the back ferrule 30 and frontferrule 24 axially advance against their respective camming surfaces 26and 20. This causes a radially inward compression of the ferrulesagainst the outer surface of the conduit 18 to effect grip and seal. Anouter conical surface 24 a of the front ferrule 24 engages the bodycamming surface 20, while a conical or tapered surface 30 a of the backferrule engages the frusto-conical camming surface 26 of the frontferrule 24. In the exemplary fitting assembly of FIG. 2, conduit grip isprimarily achieved with the back ferrule, with the front ferruleprimarily providing a fluid tight seal. However, in some designs thefront ferrule may also grip the conduit and the back ferrule may alsoprovide a fluid tight seal. Thus, the term “conduit gripping device” mayinclude two distinct functions, namely conduit grip and seal, whether ornot a specific conduit gripping device performs one or both of thosefunctions. The present inventions may alternatively be used with singlegripping device style fittings in which a single conduit gripping deviceperforms both the conduit grip and seal functions, and still furtheralternatively may be used with fittings that use more than two conduitgripping and sealing devices. Although not limiting the scope of thepresent inventions, the exemplary fitting design of FIG. 2 is well knownand commercially available from Swagelok Company, Solon, Ohio. Thesefittings, other than with the retaining feature of the presentdisclosure, are also further described in a number of issued and pendingpatent applications, including U.S. Pat. Nos. 5,882,050 and 6,629,708which are fully incorporated herein by reference. The fitting of FIG. 2herein may operate as described in such patents, but are modified asdescribed herein to provide a discontinuous cartridge, subassembly orpreassembly for retaining at least one conduit gripping device with oneof the fitting components, as set forth below.

The retaining structure or mechanism 40 is provided for retaining theconduit gripping devices 24, 30 together with one of the fittingcomponents 12, 14 as a discontinuous unit, cartridge, preassembly orsubassembly 25 prior to connecting with the mating fitting component soas to install the conduit gripping devices onto the conduit 18. Althoughvarious embodiments and drawings herein may illustrate the retainingfitting component joined with the mating fitting component or assembledwith the mating fitting component on a conduit end, those skilled in theart will readily appreciate from the drawings that the retaining fittingcomponent and at least one conduit gripping device may be retainedtogether as a discrete and separate subassembly or cartridge 25 prior tothe retaining fitting component being joined to the mating fittingcomponent

In the exemplary embodiments herein, two conduit gripping devices may beretained with the female threaded nut 14 as a discontinuous cartridge25, but alternative embodiments may be realized with a single conduitgripping device or more than two gripping devices, or with male threadednuts, or any combination thereof. For the case of multiple conduitgripping devices or a ferrule set, we refer to the in-board conduitgripping device (for example, the front ferrule 24 in the embodiment ofFIGS. 1-3) as the retaining conduit gripping device. Alternativeembodiments however may utilize a retaining structure that cooperateswith the back ferrule 30 as the retaining conduit gripping device.

The term “connecting” and variations thereof as used herein with respectto the discontinuous cartridge 25 means that the conduit grippingdevices and the retaining fitting component are initially formed ormanufactured as separate, discrete and distinct parts, and then retainedtogether in a discontinuous manner so as to be able to be easily joinedwith the mating fitting component (in the present example, a malethreaded body 12) into a fitting assembly 10. Thus, a final assemblyprocess may consist of joining or connecting together two parts, thebody 12 and the cartridge 25 having the conduit gripping devices 24, 30retained with the nut 14.

A benefit of a cartridge design with the female fitting component isthat the ferrules are retained within the machined socket of the nut,with the inboard end 14 b (FIG. 1) extending preferably but notnecessarily axially past the front end of the front ferrule. Theferrules 24, 30 thus are somewhat shrouded and protected from possibledamaging impacts against the ferrule surfaces.

In a somewhat more specific embodiment of the cartridge concept, theretaining structure typically although need not be realized in the formof an interfering surface, structure or member of the retaining fittingcomponent that resists or inhibits removing the conduit gripping devicesafter the cartridge is assembled by interfering with a surface, memberor structure that is part of at least one of the conduit grippingdevices. In the case of two conduit gripping devices, the inboard devicetypically will include a structure, surface or member that cooperateswith the interfering structure, surface or member of the fittingcomponent.

The retaining structure 40 may be realized in many different ways, butin general may include a first retaining portion 42 that is associatedwith one of the conduit gripping devices, and a second retaining portion44 that is associated with the fitting component being used to form thesubassembly 25.

The first retaining portion 42 may be associated with the front ferrule24, and the second retaining portion 44 may be associated with thefemale threaded nut 14. We also herein refer to the fitting componentthat is used to form the discontinuous cartridge as the retainingfitting component to distinguish it from the mating fitting componentthat is joined or connected to the retaining fitting component duringassembly and pull-up. In many cases, the retaining fitting component maybe modified to include the second retaining portion 44, but inalternative designs the retaining fitting component may be aconventional design without modification, but in any event will have asurface or structure therein or associated therewith that functions asthe second retaining portion 44. Thus, even though the fitting assembly10 may comprise three or more discrete elements (two fitting componentsand one or more conduit gripping devices), final assembly may if sodesired involve two parts—the cartridge and the mating fittingcomponent—that are joined together on a conduit end to make up thefitting assembly.

In many applications, it may be desirable after a partial or completepull-up to be able to remove the retaining fitting component withoutdisturbing the one or more conduit gripping devices. For example, aftera fitting assembly 10 has been completely pulled up onto a conduit, theconduit gripping devices typically although not necessarily have beenplastically deformed into a gripping engagement against the conduit 18outer surface. It is not uncommon for assembled fittings to be laterdisassembled in order to allow maintenance and repair of one or morefluid components in a fluid system. After the repair or maintenance iscompleted the fitting is reassembled and retightened. This process iscommonly referred to in the art as disassembly and remake. But in orderto perform many repair and maintenance activities, the nut 14 often mustbe removed, or at least be slid axially back or away from the body 12 inorder to allow the conduit to be withdrawn from the body 12. Typically,it will be desired to leave the one or more conduit gripping devicesattached to the conduit, and even if that is not a desired outcome, itmay often be desired to allow the nut to be pulled axially back awayfrom the ferrules, which may not be possible unless the nut and ferruleshave become released or separable during pull-up from each other.Therefore, it may be a desirable option that in such cases the nut andconduit gripping devices become separable during a partial or completepull-up, at least to the extent that the ferrules and the retainingstructure do not interfere with backing the retaining fitting componentaway from the mating fitting component and conduit gripping devices. Thepresent inventions contemplate, as an optional feature, that theretained conduit gripping devices and the retaining fitting component,and particularly the retaining structure, initially assembled in theform of the discontinuous cartridge, can be separated or disengaged evenafter the conduit gripping devices have been fully installed on theconduit. In other words, the retaining structure 40 may be designed soas to decouple from the one or more conduit gripping devices after apartial or complete pull up of the fitting assembly onto the conduit.Exemplary embodiments of this optional feature will be discussedhereinbelow.

It is also important to note that the retaining structure 40 ispreferably although not necessarily designed so that prior to or after apartial or complete pull-up the retaining structure does not appreciablyor adversely affect the form, fit and function of the fitting componentsand the conduit gripping devices. In other words, the retainingstructure preferably does not affect or alter the manner in which thefitting components and the conduit gripping devices move and deformduring pull-up so as to effect a conduit grip and seal. Still further,it is preferable although not necessarily required that the retainingstructure 40 not interfere with remake of the fitting assembly, eitherwith the original conduit gripping devices that were used in the fittingassembly, or if different conduit gripping device are used for remakebut with the original nut and body. For example, in some instances,after a maintenance or repair activity the original ferrules that arestill attached to the conduit might no longer be used for re-make. Insuch cases it is not uncommon to simply cut off the conduit end that hasthe original ferrules. A new ferrule or ferrule set may then be usedwith the original nut and body for the re-make operation. Since this istypically a field-based operation in situ, there may no longer be a needfor a cartridge configuration but rather the installer can simply use anew ferrule or ferrule set. Alternatively, remakes may also be performedwith a new cartridge if so desired. As a further alternative embodiment,the retaining structure may be configured so that the original retainingfitting component and retaining structure may be re-used to hold a newferrule or ferrule set.

The design of the retaining structure 40, including the location, shape,size, length and profile of the retaining member 46, may depend in parton the design of the cooperating second retaining portion 44. The designof the retaining structure 40, including the design of the firstretaining portion 42 and the second retaining portion 44, may alsodepend in part on how robust a connection is desired between theretaining fitting component and the conduit gripping devices, in otherwords, the nature of the retention force desired. For example, in someapplications it may be desired to have the ferrules 24, 30 strongly andsecurely retained with the fitting component 14 so that the ferrules donot fall out or get knocked out during handling, shipping or exposure toother force applying environments, while in other applications such astrong retention force may not be needed. As another example, in someapplications it may be desired to have the ferrules snugly held togetherand retained with the fitting component, while in other applications itmay be more desirable to have the ferrules somewhat loosely heldtogether and retained with the fitting component. Looser retention ofthe ferrules in the nut 14 may facilitate pull-up of the fittingassembly by not interfering with centering of the ferrules as the nut 14is initially rotated relative to the body 12. In this disclosure werefer to a loose connection or assembly to mean that the one or moreconduit gripping device(s) has some freedom of movement along one ormore axes to align and center during a finger-tight or pull-upoperation. This alignment may present itself, as an example, when theconduit is inserted through the center bores of the conduit grippingdevices and the conduit gripping devices are able to center and align oneither the conduit, or relative to each other, the body, or the nut orany combination thereof. By way of example, a loose connection may beone that allows for the conduit gripping devices to move freely or atleast to be able to easily adjust alignment to make contact with thecamming surfaces in the fitting body 12—for example surface 20 of FIG.3—and the nut 14—for example surface 34 of FIG. 3—and in the case of twogripping devices contact between the surfaces 26 and 30 a forexample—with only a finger-tightening of the nut. This assures thecorrect starting position for pull-up by turns The term “loose” does notimply or require complete freedom of movement is required, but isdistinguished from a snug or tight assembly in that the conduit grippingdevices are able to center and align during the fitting assembly andinitial tightening process or at least assembling to a finger-tightposition. These are just a few of the criteria that may be consideredwhen designing the retaining structure 40.

The second retaining portion 44 may also be designed to achieve thedesired retaining force for the subassembly 25 prior to assembly withthe mating fitting component. The second retaining portion may alsooptionally be designed to facilitate release of the retaining fittingcomponent from the one or more conduit gripping devices after assemblywith the mating fitting component, for example after or during a partialpull up or a complete pull up of the fitting assembly onto a conduit.

The retaining structure 40 may also be designed such that the ferrules24, 30 are somewhat loosely retained and may even have a slight rattlewhen the nut 14 is gently shaken. This looseness may in someapplications and embodiments facilitate final assembly with the secondor mating fitting component (in this example the body 12), especially inallowing the ferrules to center and align during pull-up of the fittingassembly 10. In alternative embodiments, however, the ferrules 24, 30may be snugly or even tightly retained in the nut 14. In any case, it iscontemplated that after the front ferrule 24 has been inserted (the backferrule being inserted first for a two ferrule fitting) that theretaining structure 40 will prevent or inhibit the front ferrule 24 (aswell as the back ferrule for a two ferrule fitting assembly) fromdropping out of the nut 14, even if the nut is dropped or otherwiseexposed to shock or other adverse forces prior to assembly with themating fitting component 12.

A general concept of the present disclosure, the retaining structure 40may have a retaining position and a release or disengage position. Inthe retaining position the conduit gripping devices and the retainingfitting component form the discontinuous cartridge 25. In the releaseposition, the retaining fitting component is separable from the conduitgripping devices. Preferably, the retaining structure is in the releaseposition after a partial or complete pull-up but not in a finger-tightposition. For example, the retaining member 46 may be a structure thatis movable relative to the retaining fitting component so as to have afirst axial position at which the retaining member 46 cooperates withthe second retaining portion 44 of the retaining fitting component toretain the ferrules, and a second axial position at which the retainingmember 46 releases from the second retaining portion 44. The retainingstructure 40, and in a particular example the retaining member 46, mayalso optionally exhibit a first radial position and a second radialposition at the first and second axial positions respectively as will befurther described hereinbelow. In still other embodiments, the retainingmember 46 may have first and second radial positions at a single axialposition.

We now describe a variety and number of different embodiments,techniques and methods for realizing a cartridge nut for conduitfittings, with the above description generally applicable to the variousembodiments herein. Additional aspects and features described below alsoapply to the various embodiments and are not limited in application tothe specific embodiment being described.

In the exemplary embodiment of FIGS. 1-3, as contrasted with the frontferrule designs of the above incorporated patents as well as otherconventional ferrule designs and conduit gripping device designs, thefront ferrule 24 herein may include the first retaining portion 42,realized in this embodiment in the form of a retaining member which maybe, for example, an annular rearward extension or protrusion 46, in thisexample a flange-like annular member. The retaining member 46 may takeon any shape or configuration that is compatible with the secondretaining portion 44 of the retaining fitting component or nut 14, sothat the retaining member 46 and the nut 14 coact to retain the ferrules24, 30 together with the nut 14 as a discrete and discontinuoussubassembly 25.

As best illustrated in FIG. 3, the extension 46 may be generally annularand may taper outwardly, both radially and axially, from a back wall 41of the front ferrule 24, or as in FIG. 3 from a corner portion of thefront ferrule at the juncture of the tapered surface 24 a and the backwall 41. However, alternatively the extension 46 may extendsubstantially radially from the back wall 41. The location, shape, size,length and profile of the extension or protrusion 46 will depend in parton the design of the cooperating second retaining portion 44 of the nut14. For example, the extension 46 need not be a continuous annularpiece, but may include slots or other voids to increase the flexibilityof the extension. In other embodiments the extension 46 need not beannular, but could have a hemispherical or other arcuate profile, ornon-arcuate. The first retaining portion 42 may also extend from aportion of the front ferrule 24 other than the back wall 41. In such acase it will be desirable that the first retaining portion be disposedon the front ferrule at a location that will not adversely influence theoperation of the ferrule, for example, the camming action with the body12 or the camming action with the back ferrule.

The second retaining portion 44 may be realized in the form of a recessor groove 48 that is formed in a generally cylindrical interior wall 50of the retaining fitting component, in this example the nut 14. Thediameter of the cylindrical interior wall 50 is generally determined asa function of the conduit 18 outer diameter and the diameter of themating body 12 so as to accommodate the threaded connection 16.Alternatively, the interior wall portion 50 need not be cylindrical butmay have a taper having a radially decreasing dimension in the directionof the back or outboard end 14 a of the nut. Some nuts may include sucha taper as a gauge for verifying maximum axial depth of the threads 16b. The groove 48 may be of such radial and axial depths preferably as tofreely or loosely receive the distal end portion 46 a of the extension46. However, in alternative configurations the groove 48 may be of suchaxial and radial depths as to maintain contact with the distal end 46 aof the extension 46. Having the extension 46 loosely received in thegroove 48 does not necessarily imply that there is no contact betweenthe extension 46 and the defining wall of the groove 48, but rather thatthe retained front ferrule 24 has some degree of play or looseness evenwhile retained with the nut 14. This may allow for easier alignment andcentering of the ferrules 24, 30 to the finger tight position asillustrated in FIG. 3 without undue friction between the extension 46and the nut 14. Note that for the two ferrule embodiment of FIGS. 1-3,the back ferrule 30 is inserted first, then the front ferrule 24 isinserted, so that the front ferrule acts to retain the back ferrule aswell.

Since the wall portion 50 typically has a diameter that is about thesame as the minor diameter of the threads 16 b, it is preferred thoughnot required that the maximum outer dimension of the extension 46 byless than or equal to the diameter of the wall portion 50. This allowsthe extension 50 to easily clear the threads 16 b so that the frontferrule 24 may be easily inserted into the nut 14.

Axially disposed between the outboard end 50 a of the cylindrical wall50 and the groove 48, an optional inwardly tapered portion 52 may beprovided. This optional feature may be in the form of a frusto-conicalsurface that tapers radially inwardly towards the back end 14 a of thenut 14. This optional surface may have a profile or contour that isother than a frusto-conical surface. As the front ferrule 24 is insertedinto the nut 14, the extension 46 engages the tapered surface 52, whichsomewhat resists further insertion of the ferrule 24. As the frontferrule 24 is further axially advanced into the nut 14 interior, theextension 46 will inwardly bend somewhat until the distal end 46 clearsthe tapered surface 52, at which point the extension 46 may exhibit asnap action sound or feel as the extension 46 enters the groove 48. Theangle of the taper of the optional surface 52 may be selected as neededfor providing the amount of bending or deflection desired of theextension 46. We have found, for example, that an angle of about 20° toabout 40° works well but the designer may choose any angle that issuitable for a particular design. The optional use of the taperedsurface 52 may provide an indication that the ferrules are in place andgenerally concentrically aligned with the axis X before applying thegreater axial force needed to snap the ferrules into the nut 14. Thetapered surface 52 is optional in that the extension 46 may be sized soas to slightly engage the cylindrical surface 50 before entering thegroove 48, however, in some embodiments this may be less desirable asthe cylindrical wall 50 is substantially longer than the tapered portion52, and the extension 46 may also interfere with the threads 16 b.Although the extension 46 may have line to line clearance with the minordiameter of the threads 16 b, it is preferred that there be at least aminimal but definite clearance between the extension 46 and the nutthreads 16 b to facilitate inserting the front ferrule 24 into the nut14.

Once the extension 46 is positioned within the groove 48, as in FIG. 1,the ferrules 24, 30 are retained with the nut 14 as a discontinuouscartridge 25. There may be but need not be some inward radial plasticdeformation of the extension 46 as it is pushed along the taperedsurface 52, but preferably the extension 46 will at least partiallyreturn towards its initial form so that the outer diameter of the distalend 46 a is greater than the smallest diameter of the tapered portion52. This will cause an interference between the distal end 46 a and thenut 14 so as to keep the ferrules 24, 30 retained with the nut 14.Although in FIGS. 1-3 there appears to be direct contact between theextension 46 and the defining wall of the groove 48, such is notrequired, and preferably there will be a small gap therebetween so thatthe front ferrule 24—and hence the back ferrule 30 as well—are somewhatloosely retained in the nut 14 so as to facilitate make up to the fingertight position when the subassembly 25 is joined to the mating fittingcomponent or body 12.

In the embodiment of FIGS. 1-3, the groove 48 may be realized by twocurved or otherwise tapered portions 54 and 56. The shape or contour ofthe groove 48 walls need not be curved but may have other shapes andcontours as needed, for example, frusto-conical shapes. The groove 48also may be realized alternatively with a single radius curved surface(see FIG. 7A for example herein) rather than the use of two differentradius curved surface portions 54, 56. The two curved surface portions54,56 also may but need not share a common center, and the curvedportions need not be arcuate but may have any suitable shape to achievethe retaining function in cooperation with the first retaining portion42.

The first curved portion 54 of the groove 48 has an increasing radialdimension towards the back end 14 a of the nut. This radial dimension ofthe first curved portion 54 may become greater than the smallestdiameter of the tapered portion 52, and preferably although notnecessarily greater than the diameter of the cylindrical wall 50 so asto freely accommodate the extension 46. The first curved portion 54 mayjoin the tapered surface 52 with the second curved portion 56. Thesecond curved portion 56 has a decreasing radial dimension towards theback end 14 a of the nut.

The first curved portion 54 functions to allow the extension 46 to snapinto or otherwise be received in the groove 48 after the front ferrule24 has been axially pushed or inserted into the nut 14 so as to move thedistal end portion 46 a over and past the tapered surface 52. The frontferrule 24 and the groove 48 may be dimensioned such that as an option,a tactile or audible snap or click or both may be sensed by anassembler. For example, the extension 46 may act as a clip or tang thatsnaps into the groove 48. The distal end 46 a of the extension may havea greater radial dimension than the groove 48 so that a surface portion55 interferes with a portion of the extension 46 to inhibit or resistremoval or disassembly of the ferrules from the assembled discontinuouscartridge 25.

The radial outermost dimension of the extension 46, the depth of thefirst curved portion 54, and the degree of inward bending to which theextension 46 is subjected, may also be chosen such that when thecartridge 25 is in the retained configuration of FIG. 1, the ferrules24, 30 are somewhat loosely retained and may even have a slight rattlewhen the nut 14 is gently shaken. This looseness may in someapplications facilitate final assembly with the second or mating fittingcomponent (in this example the body 12), especially in allowing theferrules to center and align during pull-up of the fitting assembly 10.In alternative embodiments, however, the ferrules 24, 30 may be snuglyor even tightly retained in the nut 14.

FIGS. 2 and 3 therefore show the subassembly 25 after it has been joinedto the second or mating fitting component 12 to a finger tight position.In this position, the extension 46 is axially disposed within the groove48, and in this embodiment with the parts snugged up the extensiondistal end 46 a is axially near or adjacent the second curved portion56. From the finger tight position, the body 12 and nut 14 may befurther tightened together by relative rotation so as to completelypull-up the fitting assembly 10 so that the ferrules 24, 30 form a fluidtight seal and grip of the fitting assembly 10 on the conduit 18. As thenut 14 axially advances toward the body 12 during pull-up—for examplefrom right to left in the illustration of FIG. 3—the distal end 46 a ofthe extension engages the second curved portion 56 of the groove 48.Because the second curved portion 56 tapers radially inwardly towardsthe back end of the nut 14, the extension 46 will be compressed radiallyinwardly as the nut 14 advances during pull-up. This further bending ofthe extension 46 may be used to plastically deform the extension 46 sothat it takes a set sufficient to allow the outermost radial dimensionof the extension 46 to be preferably less than or about equal to thesmallest radial dimension of the optional first tapered portion 52. Ifthe first tapered portion 52 is not used, then the extension 46preferably takes a set so that the outermost radial dimension ispreferably less than or about equal to the diameter of the cylindricalwall 50. By allowing for the extension 46 to clear these radialdimensions, the nut 14 may easily be backed off from the fittingassembly 10 after a complete pull-up, for example, during a maintenanceor repair activity or other activity in which the pulled-up fitting isdisassembled. In alternative embodiments, however, it may not benecessary to deflect or bend the extension 46 anymore than is needed tofacilitate removing the nut 14 after a complete pull-up, and in somecases there may be no need to deform the extension 46 or to provide aclearance between the extension 46 and the nut 14. The fitting 10 may bedisassembled even if there is still some interference or frictionbetween the extension 46 and the nut 14.

An optional second tapered surface 58 may be used to still furtherdeflect the extension 46 inwardly during pull-up to reduce interferencebetween the extension 46 and the nut 14 when the fitting isdisassembled. Note in this example that the second tapered surface 58has a decreasing radial dimension axially towards the back end 14 a ofthe nut. Preferably, although not necessarily, the largest radialdimension of the second tapered surface 58 is less than the smallestradial dimension of the first tapered surface 52. The extension 46 maytake a permanent or plastic set or may have some elastic spring-backdepending on factors such as the type of material of the ferrule 24,then thickness of the extension 46 and so on. It is contemplated thatthe extension 46 will be inwardly deflected enough to overcome thedesigned-in retaining force between the ferrule 24 and the nut 14. It isalso contemplated that the extension 46 be positioned on the ferrule 24body so as to not interfere with the back ferrule 30 or the nut 14during pull-up of the fitting, or during re-make of the fitting. Theoptional second tapered surface 58 may adjoin the interior back wall 34of the nut 14 which may itself have various optional tapers andcontours, and forms a socket 60 that receives the back ferrule 30.

The extension 46 need not be circumferentially a single piece. Forexample, the extension 46 may comprise several axially extendingfingers, such as three or more for example evenly positioned about theaxis X, that snap into the recess 48. The extension 46 also need not beintegrally machined with the ferrule 24, but may alternatively be anattached member or members.

With reference next to FIGS. 4A-4D, we show illustrations from an FEAmodel of how the ferrules 24, 30 and the nut 14 cooperate duringassembly so as to realize a discontinuous cartridge 25. It will be notedthat FIGS. 4A-4D (as well as FIGS. 5A-5D) illustrate another embodimentof the retaining structure, although the basic concept of a recess orgroove in the nut 14 cooperating with an extension of the front ferrule24 may be the same as described hereinabove and will generally operatethe same except as otherwise noted. The nut 14 interior socket 60 thatreceives the back ferrule 30 also may have a simpler geometry becausethe socket 60 geometry does not substantially affect the retainingfeature. The five views are actually snapshots of a full FEA video ofwhat happens when the ferrules 24, 30 are axially pushed into the nut 14so as to be in a retained position.

The FEA illustrations herein also include simplified markings or contourlines to show stress regions to further elaborate on what happens to theferrules during assembly. Although in the FEA figures we show many ofthe parts cross-hatched, such is for clarity as to the view beingillustrated. For parts that are undergoing stress and having asubstantial number of contour lines to represent such stress, we leavethe cross-hatching out of the drawing for that part. Note that thecontour lines and stress regions are not assigned specific values forthe drawings. However, in general, the smaller and tighter the region,the higher the stress.

FIG. 4A illustrates the parts with the back ferrule 30 positioned in thesocket 60 of the nut 14 and the front ferrule 24 positioned in the nut14 so that the extension 46 contacts the first tapered portion 52. Thegeometry of the recess or groove 48 is modified in this embodiment andtherefore indicated with a prime (′) notation. The recess 48′ in thisexample comprises a single simple arc which may but need not be ahemispherical shape. The recess 48′ thus still includes a first portionthat tapers radially outward and a second portion that tapers radiallyinward. In practice, the ferrules 24, 30 may be but need not be insertedinto the nut 14 while the nut is in an upright orientation. Note that inthis pre-retained position of FIG. 4A, there may be an axial gap 64between the front and back ferrules.

In FIG. 4B, the front ferrule 24 has been axially displaced into the nut14 such that the distal end 46 a of the extension is pressed along thefirst tapered surface 52, which causes an inward deflection of theextension 46. This bending or deflection causes stress regions 66 toappear in the extension 46 and related stress regions 68 in the nut.Further axial insertion of the front ferrule 24 leads to the positionillustrated in FIG. 4C in which the distal end 46 a of the extension hasjust moved past the first tapered surface 52. This results in lowerstress concentrations 66 a in the extension 46 as compared to theposition of FIG. 4B, indicating that in this embodiment the extension 46has taken a set or been somewhat plastically deformed, however, there isstill residual stress in the extension 46. Note also that the gap 64 hasclosed somewhat, compared to FIG. 4A.

Further axial displacement or insertion of the front ferrule into thenut 14 leads to the position illustrated in FIG. 4D in which the distalend 46 a of the extension has cleared the reduced inner diameter of thenut interior wall and snapped into or otherwise become positioned in thegroove 48′. In this position, the gap 64 may be minimal or even zerowith direct contact between the front and back ferrules 24, 30 but suchcontact is not necessarily required. With the extension 46 nowpositioned in the groove 48′, the ferrules 24, 30 are retained in thenut 14 as a cartridge 25. The extension 46 may be somewhat loose in thegroove 48′, yet there may still be residual stress 66 b in the extension46, and as illustrated the extension 46 may have taken a set throughplastic deformation due to the bending action of inserting the ferrule24 into the groove 48′.

With reference next to FIGS. 5A-5D, the fitting assembly 10 is modeledusing FEA to show what happens as the assembly is pulled-up from thefinger-tight position (FIG. 5A) to a completely pulled-up position (FIG.5D). As illustrated in FIG. 5A, in the finger tight position, theferrules 24, 30 are typically snugged up against each other between thenut 14 and the body 12. The extension 46 is disposed in the groove 48′.The extension 46 may have some residual stress as indicated by thestress regions 66 b. In this example, the nut and body may be threadablyjoined so that relative rotation of the nut and body produces an axialmovement of the ferrules towards the body. The back wall 34 of the nut14 acts as a drive surface and engages the back wall 32 of the backferrule 30. This pushes the back ferrule 30 against the front ferrule 24which is therefore pushed against the camming surface 20 of the body 12.

In the position of FIG. 5B, the nut 14 has advanced sufficiently thatthe extension 46 engages the second curved portion 56 of the groove 48′.The extension 46 is further radially deflected or bent inwardly.Moreover, the extension 46 may undergo further inward deflection becausein this exemplary fitting design, the back ferrule 30 tends to push theback end of the front ferrule 24 radially outward, thus pushing theextension 46 harder against the second curved portion 56 of the groove48′, thereby producing stress regions 78 where the extension 46 contactsthe groove 48′.

FIG. 5B may also be considered a pre-swage position, such as may beachieved using a swaging tool during an assembly step that precedesfinal tightening. Oftentimes, it may be desirable to pre-install theferrules and nut onto the conduit end before the final assembly stepsare taken to make up the fitting and tighten the fitting onto a conduit.This often is the case, for example, with larger conduit diameters inwhich the pull-up forces can be substantial and facilitated by anautomatic or manual pre-swaging tool. Exemplary tools include an AHSUAir Actuated Hydraulic Swage Unit (automatic) and an MGST ManualGageable Swage Tool (manual) available from Swagelok Company, Solon,Ohio. The retaining structure 40 may be designed to cooperate with apre-swaging operation so that the retaining structure no longer retainsthe nut with the ferrules, or only loosely retains them together. Thismay be achieved, for example, by designing the retaining structure andthe pre-swaging tool to work together so that when a pre-swage operationis performed to a position such as in FIG. 4B, the extension 46 has beensufficiently deformed inwardly to allow the nut to be easily backed offof or separated from the ferrules, even though the ferrules have beenpre-swaged into gripping engagement with the conduit.

Upon further tightening of the nut 14 and body 12, the front edge 30 bof back ferrule 30 begins to bite into the conduit outer surfacecreating a stress region 80 in the conduit 18, and the front ferrule 24begins to tightly engage the camming surface 20 to form a fluid-tightseal, thus also inducing stress regions 82 in the conduit. This is thecondition illustrated in FIG. 5C. Note that the extension 46 in thisview has cleared the groove 48′ and engages an outboard cylindrical wallportion 84 of the nut 14. This wall portion 84 may alternatively betapered (for example, surface 58 in FIG. 3) to further cause theextension 46 to be radially inwardly deflected. Bending of the extension46 against the wall portion 84 may also induce stress 72 in the nut.

In FIG. 5D the fitting assembly 10 has been completely pulled-up toresult in the ferrules 24, 30 forming a fluid tight seal and conduitgrip with the body 12 and the conduit 18. In this example, the extension46 has been deflected or bent into an almost parallel relationship withthe outboard cylindrical wall portion 84. Note in comparing FIG. 5D withFIGS. 5A-5C how the back end of the front ferrule 24 rotates radiallyoutwardly during pull-up, caused by the back ferrule 30 pushing againstthe camming surface 26. This deformation will allow for substantiallyreduced or eliminated frictional engagement between the extension 46 andthe groove 48′ as well as the inboard cylindrical wall 50 and thethreads 16 b when the fitting 10 is disassembled. Note that in thevarious embodiments illustrated herein, the retaining structure 40 andoperation thereof do not significantly or noticeably affect the pull-upoperation for the fitting assembly 10.

With reference to FIGS. 5E and 5F, should it be desired to disassemblethe fitting 10 after a complete pull-up, the nut 14 may be reverserotated with respect to the body 12. Because the extension 46 no longerengages with the groove 48′, or engages with substantially reducedcontact and interference, the nut 14 may be easily backed off thefitting 10 assembly, for example allowing the nut to be axiallyseparated from the ferrules, thus allowing the fitting 10 to beseparated or otherwise disassembled as needed. Typically, although notrequired, the ferrules 24, 30 remain attached to the conduit 18 so as tofacilitate remake of the fitting assembly 10.

The retaining member 46 may be made of any suitable material, includingelastomer, plastic and metal and preferably sturdy enough to retain theferrules with the nut 14 as a cartridge 25. Use of a metal retainingmember 46 allows for all metal fitting assemblies for high temperatureapplications or use with fluids that may damage an elastomer or plastic.Suitable metals may include but are not limited to stainless steel,brass, copper, steel and so on to name just a few of the many availablematerials.

It is also important to note that the first retaining portion 42, whichin the exemplary embodiment of FIGS. 1-3 is an integrally formed ormachined part of the front ferrule 24, may alternatively be a separatepiece that attaches to the front ferrule, for example.

Accordingly, one or more of the present inventions facilitates amechanism or structure and method by which one or more ferrules orconduit gripping devices may be retained with a fitting component as adiscontinuous cartridge 25, with the retaining structure then beingaltered during pull-up (either a complete pull-up or a partial pull-upas needed) so that the nut 14 is released and may subsequently bewithdrawn or pulled back from the fitting assembly.

Use of the discontinuous cartridge 25 facilitates providing ferrule setsto the end user in which the ferrules and nuts are properly matched atthe manufacturer. This can significantly simplify inventory control andreduce final assembly time. The embodiments herein also allow for acartridge design in which the retaining fitting component may be usedfor fitting assemblies that do not need or have the retaining member 46.

In an exemplary method, one or more conduit gripping devices areretained with a retaining fitting component as a discontinuouscartridge. This discontinuous cartridge forms a first part of a two partfitting assembly. The cartridge is then joined with the second part ofthe fitting assembly and a portion of a conduit. During at least apartial pull-up of the fitting assembly, the conduit gripping devicesbecome attached to the conduit and become disengaged from the retainingfitting component so that the retaining fitting component may be removedfrom the fitting assembly after the partial pull-up while the one ormore conduit gripping devices remain attached to the conduit. In a morespecific embodiment, the method may include the steps of retaining oneor more conduit gripping devices with a retaining fitting component as adiscontinuous cartridge, joining the cartridge to a second fittingcomponent on a conduit to cause the conduit gripping devices to attachto the conduit, and disengaging the retaining fitting component from theconduit gripping devices so that the retaining fitting component may beremoved from the fitting assembly after a partial pull-up while the oneor more conduit gripping devices remain attached to the conduit. Instill a more specific embodiment, the conduit gripping devices may besnapped into place in the retaining fitting component to form thecartridge.

With reference to FIG. 6, we illustrate another embodiment of aretaining structure 100 that may be used to retain one or more conduitgripping devices, for example ferrules, within a retaining fittingcomponent. In this embodiment, the retaining fitting component may berealized in the form of a female nut 102. Rather than using a grooveformed in the nut as in the embodiments of FIGS. 1-5 herein, theretaining structure 100 may include a first retaining portion such as,for example, a front ferrule 24 extension 46 that engages a secondretaining portion 104, such as, for example, the inner cylindricalsurface 104 of the nut 102. Frictional engagement between the extension46 and the inner cylindrical surface 104 will act to retain the ferrules24, 30 within the nut 102 as a discontinuous subassembly 106. FIG. 6illustrates the subassembly 106 joined with the body 12 in afinger-tight position. The frictional engagement between the extension46 and the inner cylindrical surface 104 of the nut may be enhanced byproviding a modified finish to the inner cylindrical surface 104 of thenut, such as, for example, roughening, shallow grooves, knurling and soon. The nut 102 may further include an axially shortened radially inwardtapered or contoured surface 108 that tapers inwardly towards the backend of the nut 102. In the embodiment of FIG. 6, this surface 108 may befrusto-conical, but any contour may be used. This short tapered surfacemay be angled more sharply, for example, about 45° to about 60° degreesrelative to the axis X, so that the front ferrule 24 sits against orengages this surface when placed into the nut 102 after the back ferrulehas been installed in the nut 102. Other angles may be used as needed.During pre-swaging or pull-up operations, the extension 46 will engagethis tapered surface 108 and be radially deflected or bent inward sothat during subsequent disassembly the extension 46 does not present asignificant frictional resistance to removing or withdrawing the nut102. A second tapered surface 110 may be used to further deflect theextension 46 during pull-up.

With reference to FIGS. 7A and 7B, we illustrate another embodiment.FIG. 7A illustrates a conduit fitting assembly 150 having a firstfitting component 12, for example a male threaded body, and a secondfitting component 152, for example a female threaded nut. The frontferrule 24 and the back ferrule 30 may be, but need not be, the samedesign as in the embodiment of FIGS. 1-3 herein. A retaining structure154 is provided for retaining the ferrules 24, 30 (or a single ferruleas the case may be) with the second fitting component 152 as adiscontinuous unit, subassembly or preassembly 156. FIG. 7A shows thesubassembly 156 already joined with the first fitting component 12 andinstalled on the conduit 18 in a finger-tight position.

The retaining structure 154 in this embodiment includes a firstretaining portion 158 associated with the front ferrule 24, and a secondretaining portion 160 associated with the nut 152. The first retainingportion 158 may be realized, for example, in the form of an extension162 which may be similar in design and operation to the extension 46described hereinabove. Thus the extension 162 may taper in a radial andaxial direction. The second retaining portion 160 may be realized in theform of a groove 164 formed in the interior cylindrical surface 166 ofthe nut 152.

The groove 164 receives the distal end 162 a of the extension 162 in asimilar manner as the embodiment of FIGS. 1-3 hereinabove. Associatedwith the groove 164 is a radial flange 168 that may extend radiallyinwardly from the interior cylindrical surface 166 of the nut. Thisflange 168 may include an optional first radially inwardly taperedsurface 170 that engages the distal end 162 a of the extension 162 asthe front ferrule 24 is pushed into the nut 152. This engagementdeflects the extension 162 radially inwardly with a resulting snap orclick when the front ferrule has been sufficiently inserted so that theextension 162 is pushed past the flange 168 to be aligned with thegroove 164. This is the finger-tight position illustrated in FIG. 7A,with the ferrules 24, 30 retained with the nut 152 as a discontinuoussubassembly 156. The groove 164 and the radial flange 168 may form aninterfering surface 165 that interferes with the extension 162 to retainthe ferrules with the fitting component as a discontinuous cartridge.

The groove 164 may include an optional second radially inwardly taperedsurface 172 that causes further inward deflection of the extension 162during partial or complete pull-up of the fitting 150. This secondtapered surface 172 may further join to an optional third radiallyinwardly tapered surface 174. This third tapered surface 174 may be usedto further deflect the extension 162 during pull-up of the fitting 150.The innermost or smallest radial dimension of the third tapered surface174, or alternatively the optional second tapered surface 172, may bepreferably at least equal to or less than the diameter of the radialflange 168. This will allow for the extension 162 to be sufficientlyinwardly deflected so that the nut 152 may be easily backed off thefitting 150 during subsequent disassembly.

With reference to FIG. 7B, after a complete pull-up as illustrated, thesecond and third tapered surfaces 172, 174 have caused the extension 162to be bent or deflected radially inwardly sufficiently so that theextension 162 no longer substantially interferes with the flange 168 orthe groove 164. Also it will be noted that the back ferrule 30 haspushed the back end of the front ferrule 24 radially outward so as tofurther bend or deflect the extension 162. Although FIG. 7B is for acomplete pull-up position, the retaining structure 154 may be designedto bend the extension 162 after a partial pull-up, such as for exampleduring a pre-swaging operation.

With reference to FIGS. 8A and 8B, we show another embodiment of aconduit fitting assembly 200 that includes a discontinuous subassembly,preassembly or unit 202 having one or more conduit gripping devices 204retained with a retaining fitting component 206. In this embodiment, thefitting assembly 200 is commonly referred to as a female fitting becausethe first fitting component 208 may be realized in the form of a femalethreaded body, and the second or retaining fitting component 206 may berealized in the form of a male threaded nut. The basic structure of thefirst and second fitting components, except as otherwise noted herein,are fully described in pending U.S. patent application Ser. No.11/112,800, published as Publication no. US 2005/0242582 A1 on Nov. 3,2005 for FITTING FOR TUBE AND PIPE, the entire disclosure of which isfully incorporated herein by reference. The body 208 and nut 206 as usedherein may be, but need not be, basically the same as in the Ser. No.11/112,800 application, except that the nut 206 has been modified toinclude a recess or groove 210 formed in an inboard portion of the nut206.

In the embodiment of FIGS. 8A and 8B, a retaining structure 212 forretaining the one or more conduit gripping devices 204 (in this exampleincluding a front ferrule 204 a and a back ferrule 204 b) may include afirst retaining portion 214 in the form of a generally radial extension216 from the rearward end of the front ferrule 204 a, and a secondretaining portion 218 in the form of the recess or groove 210 formed inthe nut 206. The extension 216 cooperates with the groove 210 to retainthe one or more conduit gripping devices with the nut 206 as thediscontinuous cartridge 202. In this embodiment, the male nut 206 mayinclude a radially tapered surface 220 as per the above referenceddisclosure, and the recess 210 may be conveniently formed therein. Theoutboard portion 220 a of the tapered surface 220 will function to causea radially inward compression of the extension 216 during a partial orcomplete pull-up of the fitting 200. In the finger-tight assembly ofFIG. 8A, the extension 216 has been snapped into place in the groove 210to retain the ferrules with the nut 206.

FIG. 8B illustrates the fitting assembly 200 in a complete pull-upposition in which the extension 216 has been deflected or bent so thatupon disassembly of the fitting 200 the extension 216 will no longerinterfere with the groove 210. Note that the extension 216 has beendeflected in a counter-clockwise direction (or in-board direction, asviewed in FIG. 8B), whereas in various other embodiments illustratedherein, the extension may be deflected in a clockwise or outboarddirection. The retaining structures of the various embodiments hereinmay be designed as needed to provide a desired degree and direction ofdeflection as needed.

The front ferrule 204 a may also be provided with an optional recess orgroove 222 that may be positioned adjacent the radial extension 216 soas to facilitate the flexibility of the extension 216 to allow it to bebent or deflected as it engages the tapered surface 220 a duringpull-up.

With reference to FIGS. 9A and 9B, in still another embodiment for amale fitting 300, in this example the body 12 is formed as part of aconventional union 302. In FIG. 9A the cartridge 304 has been joined tothe body 12 in a finger-tight position but the conduit is omitted forclarity. A front ferrule 306 and back ferrule 308 are retained with theretaining fitting component in the form of a female threaded nut 310 asthe discontinuous cartridge 304. As best illustrated in FIG. 9B, thediscontinuous cartridge 304 includes a retaining structure 312 which mayinclude a first retaining portion 314 in the form of a substantiallyradial extension 316. The nut 310 may include a second retaining portion318 in the form of a radially inward tapered flange 320 and a groove322. The radial flange 318 may include a first tapered surface 324 thatcauses an inward deflection or bending of the extension 316 as the frontferrule 306 is pushed into the nut 310. The extension 316 then snapsinto the groove 322. Note that although in FIG. 9B there appears to havebeen no plastic deformation of the extension 316 during the insertionprocess, there may be some partial bending, however, the tapered surface324 preferably will bend the extension 316 just enough to allow theextension to be disposed into the groove 322, with or without aresulting small latent deformation. The groove 322 may include aradially inwardly tapered portion 326 that causes the extension 316 tobe bent towards the inboard end of the nut 310 (as viewed in FIG. 9B)during a partial or complete pull-up, similar to the bending directionof the embodiment of FIG. 8B herein. A second radially inwardly taperedsurface 328 may optionally be provided to further bend the extension 316radially inwardly during a partial or complete pull-up so that theextension 316 will not interfere with backing the nut 310 away from theassembly as needed for fitting disassembly and re-make. The frontferrule 306 may also be provided with an optional recess or groove 330that may be positioned adjacent the radial extension 316 so as tofacilitate the flexibility of the extension 316 to allow it to be bentor deflected as it engages the tapered surface 328 during pull-up.

It will be noted that in the various embodiments herein, although notrequired in all situations, the retaining structure, as well as thefitting components and the conduit gripping devices, are preferably allmetal. Furthermore, the retaining structure preferably is designed sothat during or after a partial or complete pull-up, the retainingfitting component may be axially released and moved away from theconduit gripping device or devices that the retaining fitting componenthad retained initially as a discontinuous subassembly or cartridge.

With reference to FIGS. 10 and 11, we illustrate another embodiment of acartridge nut concept. This embodiment is similar in many respects tothe embodiment of FIG. 9B and we use like reference numerals to refer tolike parts. A significant difference is that the conduit grippingdevices, in this example front and back ferrules 306, 308, are connectedtogether in a ferrule cartridge or subassembly 25 preferably prior toinstallation into the retaining fitting component 310. The ferrules 306,308 are connected by a retaining structure 400 which in this embodimentmay be realized in the form of a lip 402 that presents a recess 404 inthe rearward portion of the front ferrule. The crown portion 406 of theback ferrule 308 is received into the recess 404 to hold the ferrulestogether as a cartridge 25. The cartridge nut arrangement 304 may berealized using the retaining structure 312. The ferrule cartridge 25design is fully described in pending United States patent applicationserial no. PCT/US2009/67508 filed on Dec. 10, 2009 for FERRULE ASSEMBLYFOR CONDUIT FITTING, then entire disclosure of which is fullyincorporated herein by reference.

FIG. 11 illustrates the fitting in a pulled-up condition. Note that theradial extension 316 has been bent in an in-board or forward directionby contact with the second radially inwardly tapered surface 328 andthat the back ferrule forward portion 408 has been radially compressedinwardly to disengage or release from the retaining structure 400.

Note also that FIG. 10 illustrates how in some cases the radialextension 316 may have an inward deflection or bend produced as thefront ferrule 306 is pushed into the nut 310, caused by the inwardtapered flange 320. Also it will be noted that the nut 310 includes atapered drive surface 410 that acts as a ferrule drive surface against aback wall or driven surface 412 of the back ferrule 308 during pull-up.A third tapered surface 414 may be provided to facilitate centering theback ferrule in the nut 310 as the fitting is assembled in thefinger-tight position. This tapered surface is also shown in the otherembodiments herein (FIGS. 1-9B) and is fully described in pendingInternational application serial no. PCT/US10/32524 filed on Apr. 27,2010 for TAPERED DRIVE NUT FOR CONDUIT FITTING, the entire disclosure ofwhich is fully incorporated herein by reference.

With reference to FIGS. 12 and 13, we illustrate another embodiment of adiscontinuous cartridge nut 500, shown assembled to a mating fittingcomponent 12 such as a fitting body with a conduit end 18 (shown inphantom) in a finger-tight position. A retaining structure 40 isprovided for retaining one or more ferrules or conduit gripping devicewith the retaining fitting component 502 which may be, for example, afemale threaded nut. The retaining structure 40 includes a firstretaining portion 42 associated with one of the conduit grippingdevices, in this example the inboard front ferrule 504, and a secondretaining portion 44 associated with the retaining fitting component.Alternatively, as with many of the other embodiments herein, the firstretaining portion 42 may be associated with the back or outboard ferrule506, especially when a ferrule cartridge concept is optionally used. Inthe embodiment of FIGS. 12-17 we illustrate use of the ferrule cartridgewhich may be realized as set forth in the above incorporated patentapplication. However, use of the ferrule cartridge is optional, and inthe embodiment of FIGS. 12-17 the cartridge nut 500 design will retainboth the front and back ferrules with the retaining fitting componentwithout use of the ferrule cartridge concept.

As compared to other embodiments herein, the front ferrule 504 isprovided with a generally radial flange 508 that extends radiallyoutward from the outer surface 504 a at a rearward portion of the frontferrule 504. The flange 508 need not be radial but may extend at a rakeangle as needed or alternatively have a different profile. The angle ofthe flange 508 will be a design feature selected to achieve the desiredrobustness of the cartridge nut 500.

A distal portion 510 of the flange 508 is received in a groove or recess512 formed in the interior wall 514 of the retaining fitting component502. This recess 512 serves as the second retaining portion 44 of theretaining structure 40.

The flange 508 is sized and shaped or profiled so as to allow the frontferrule 504 to be threaded or screwed into the nut 502 via the femalethreads 16 b of the threaded connection 16 between the nut and body. Theback ferrule 506 is inserted first into the nut 502, and then the frontferrule is rotated through the female threads 16 b and positioned intothe recess 512. The recess 512 may be sized as needed to provide eithera loose retention of the ferrules within the cartridge nut 500, or amore snug retention if so desired. When the fitting is assembled to afinger-tight position as in FIG. 13, the flange 508 may abut an outboardwall portion 512 a of the recess 512. Preferably, although notnecessarily, the threads 16 b of the nut 502 extend nearly to theinboard end of the recess 512, so that the interior wall portion 514 isfairly short, allowing the flange 508 to be threaded down into the nut502 almost to the recess 512 and then snapped or otherwise pushed intoposition in the recess 512. Alternatively, the threads 16 b may extendall the way to the recess 512, or the threads may have a shorter axiallength (thus increasing the axial length of the axial length of theinterior wall 514).

With reference to FIGS. 14-16 as well as FIG. 13, the front ferrule 504may include a tapered conical outer surface 504 a that will engage thecamming surface 20 of the body 12 so that the front ferrule can functionas a conventional front ferrule. The flange 508 may be axially disposedtowards a rearward portion of the front ferrule, but alternatively theflange may be located at any convenient axial location along the frontferrule outer surface 504 a. To increase the flexibility of the flange508, the flange may be formed with a polygonal profile. In theembodiment herein, the flange 508 is formed with a hexagonal shape, withsix thread engaging hex sides such as radial tabs 516 generally evenlyspaced about the circumference of the ferrule 504. The outer surface 518of each radial tab 516 may be arcuate to facilitate screwing the flange508 past the female threads of the nut 502. For example, the arc of theouter surface 518 of each hex portion may generally conform to the majordiameter of the nut threads. Each radial tab 516 outer surface may alsoinclude a bevel or rounded portion 520 (best viewed in FIG. 16) tofacilitate threading the flange through the nut threads. The bevel anglemay generally match the thread pitch of the nut threads in the outboardfacing direction. The flange 508 will also be preferably thin enough toeasily pass along the nut threads during assembly. Moreover, each radialtab 516 may include a slight twist to match the nut thread angle.

The front ferrule 504 also includes a frusto-conical camming surface 26as is conventional, against which the back ferrule 506 engages duringpull-up.

In a manner similar to the above-described embodiments, during either apartial or complete pull-up of the fitting assembly, the nut 502 movesaxially relative to the body 12 so that the ferrules are axially engagedand radially compressed against the conduit 18. The nut 502 movesaxially faster relative to the body 12 than do the ferrules, so that thenut 504 will move past the flange 508. This causes an interferencebetween the outboard wall 512 a of the recess 512 and the flange 508. Asthe nut advances axially further, the flange 508 will be bent over andin an in-board direction as illustrated in FIG. 17. The nut may includea tapered wall portion 526 adjacent the recess 512 and having adecreasing radial dimension in the outboard direction, to facilitatebending the flange 508 during pull-up. In this manner, after at least apartial pull-up, the flange 508 has been bent sufficiently to no longerretain the front ferrule with the nut 502 and does not interfere withthe operation of the ferrules during pull-up. This will allow the nut504 to be axially withdrawn from the fitting assembly if so desired,after a partial or complete pull-up.

To facilitate the bending action of the ferrule during pull-up eachradial tab 516 may be provided optionally with a relief notch or recess522 (see FIG. 13 for example) that provides a thinned wall 524 of thehex portion. The shape, depth and size of the relief notch 522 may bedesigned as needed to facilitate bending the radial tabs 516 duringpull-up. The relief notch 522 in the drawings is illustrated on theoutboard side of the flange 508, but alternatively may be on the inboardside of the flange 508.

The flange 508, in a manner analogous to some of the embodimentshereinabove, thus has a retaining position at a first axial locationrelative to the nut 502 as illustrated in FIG. 13 and a release positionat a second axial location relative to the nut 502 as illustrated inFIG. 17. The flange in this example undergoes a radial modification ordeformation between the retaining position and the release position.

The flange 508 preferably is formed integral with the front ferrule 504during machining of the ferrule. For example, the ferrule 504 may bemachined from hex bar stock to facilitate forming the hex flange 508.Alternatively, the flange 508 may be provided as an attached additionalpiece by welding, brazing, press fit or other suitable technique, forexample, or may be a breakaway piece.

The use of multiple radial tabs 516 provides a circumferentiallydiscontinuous structure that do not take on any added hoop strengthwhile flexing or bending out of the way during pull-up, and thereforethe radial tabs can more readily disengage from the recess 512. Acontinuous or non-segmented flange, which is an alternative embodimentif so needed, would take on a hoop compression stress that could resistthe bending action, therefore other design criteria might be needed tofacilitate the bending action, for example, a thinner flange.

In the exemplary embodiments of FIGS. 18-22 (wherein the -1 designatoris used to group various alternative embodiments as well as to designatelike components of other embodiments herein as well as distinguishingalternative, different or additional components described with thisgrouping) the front ferrule 24-1 may be conventional in design, if sodesired, so that the first retaining portion 42-1 may simply be realizedin the form of the outer tapered surface 24 a-1 of the front ferrule24-1. Alternatively, the front ferrule may be modified to include astructure or feature (not shown) that will interact with the secondretaining portion 44-1, but for the exemplary embodiments such structureis not needed. In any case, the front ferrule 24-1 will coact with thesecond retaining portion 44-1 so as to retain the ferrule or ferrule settogether with the nut 14-1 as a discrete and discontinuous subassembly25-1.

The second retaining portion 44-1 may be realized in the form of aretaining member 46-1, such as an extension or protrusion from aninterior surface 48-1 of the retaining fitting component 14-1. Theretaining member or protrusion 46-1 may be a tab or tab-like structurethat extends generally radially inward to a distance by which the distalend 46 a-1 of the retaining member will prevent or inhibit the ferrules24-1, 30-1 from falling out of the retaining fitting component 14-1.However, alternatively the retaining member 46-1 may protrude inwardlyother than radially. For example, the retaining member may be canted (asshown in phantom in FIG. 18) towards the outboard end 14 a-1 of the nut14-1, which may facilitate inserting the front ferrule into the nut14-1, particularly if the retaining member 46-1 is quite stiff orresistant to bending moments. The distal end 46 a-1 may alsoalternatively have a rounded, curved or sloped contour so as to notscratch or dig into the front ferrule when the front ferrule is pushedinto the nut 14-1. Alternatively, the retaining member may be multipleextensions spaced around the interior surface 48-1, or may be an annularprojection or a series of arcuate projections, for example.

The location, shape, size, length and profile of the retaining member46-1 may depend in part on the design of the cooperating first retainingportion 42-1 of the front ferrule 24-1. The design of the retainingstructure 40-1, including the design of the first retaining portion 42-1and the second retaining portion 44-1, may also depend in part on thenature of the retention force desired. For example, in some applicationsit may be desired to have the ferrules 24-1, 30-1 strongly and securelyretained with the fitting component 14-1 so that the ferrules do notfall out or get knocked out during handling, shipping or exposure toother force applying environments, while in other applications such astrong retention force may not be needed. As another example, in someapplications it may be desired to have the ferrules snugly held togetherand retained with the fitting component, while in other applications itmay be more desirable to have the ferrules somewhat loosely heldtogether and retained with the fitting component. These are just a fewof the criteria that may be considered when designing the retainingstructure 40-1. The retaining member 46-1 may contact the front ferrule24-1 when the ferrules 24-1, 30-1 and the retaining fitting component14-1 are installed in the retaining fitting component, or may be axiallyspaced such that the retaining member only contacts the front ferrule24-1 should the front ferrule drop down into contact with the retainingmember 46-1. Looser retention of the ferrules in the nut 14-1 mayfacilitate pull-up of the fitting assembly by not interfering withcentering of the ferrules as the nut 14-1 is initially rotated relativeto the body 12-1.

The second retaining portion 44-1 may be designed to achieve the desiredretaining force for the subassembly 25-1 prior to assembly with themating fitting component. The second retaining portion may alsooptionally be designed to facilitate release of the retaining fittingcomponent from the one or more conduit gripping devices after assemblywith the mating fitting component, for example after or during a partialpull up or a complete pull up of the fitting assembly onto a conduit.

The retaining member 46-1 may be configured such that as the frontferrule is inserted into contact with and then pushed past the retainingmember 46-1 (keeping in mind the back ferrule 30-1 is installed firstfor a two ferrule fitting), the front ferrule 24-1 may optionally snapinto or otherwise be received in the socket 50-1 of the nut 14-1. Thissnap effect may occur after the front ferrule 24-1 has been axiallypushed or inserted into the nut 14-1 so as to move the enlarged back end24 b-1 of the front ferrule past the retaining member 46-1. This is theposition illustrated in FIGS. 18 and 19. The retaining member 46-1 maybe dimensioned and designed such that as an option, a tactile or audiblesnap or click or both may be sensed by an assembler as the front ferruleis pushed past the retaining member 46-1.

The radial outermost dimension of the retaining member 46-1, incooperation with the taper angle of the outer surface 24 a-1 of thefront ferrule, and the degree of bending to which the retaining member46-1 is subjected, may also be chosen such that when the cartridge 25-1is in the retained configuration of FIG. 18, the ferrules 24-1, 30-1 aresomewhat loosely retained and may even have a slight rattle when the nut14-1 is gently shaken. This looseness may in some applicationsfacilitate final assembly with the second or mating fitting component(in this example the body 12-1), especially in allowing the ferrules tocenter and align during pull-up of the fitting assembly 10-1. Inalternative embodiments, however, the ferrules 24-1, 30-1 may be snuglyor even tightly retained in the nut 14-1. In any case, it iscontemplated that after the front ferrule 24-1 has been inserted suchthat the enlarged back end 24 b-1 is axially past the retaining member46-1, that the radial dimension of the retaining member 46-1 will besufficient so as to interfere with the front ferrule 24-1 (such as theenlarged back end portion in the exemplary embodiment) to prevent orinhibit the front ferrule 24-1 (as well as the back ferrule for a twoferrule fitting assembly) from dropping out of the nut 14-1, even if thenut is dropped or otherwise exposed to shock or other adverse forcesprior to assembly with the mating fitting component 12-1. Preferably theretaining member 46-1 will interfere with the front ferrule 24-1 toretain the one or more ferrules with the retaining fitting componenteven if the retaining member is somewhat bent or plastically deformedwhen the front ferrule 24-1 is pushed into the socket 50-1.

In order to facilitate inserting the front ferrule 24-1 into the nut14-1, the retaining member 46-1 may be dimensioned so that it isbendable or flexible to allow the front ferrule to be pushed past theretaining member 46-1. Moreover, in the exemplary embodiments herein,the bendable or flexible retaining member 46-1 will also be able to beplastically deformed or bent away so as to no longer interfere with thefront ferrule 24-1. The retaining member 46-1 may be integrally machinedwith the nut 14-1 or attached in some manner.

In an alternative embodiment, rather than a member that extends from theinterior surface 48-1 of the retaining fitting component, a pin-likemember 52-1 may be inserted through a hole 54-1 formed through the nut14-1, as shown in phantom in FIG. 18. The pin-like member 52-1 mayextend down into the nut interior so as to function in a manner similarto the retaining member 46-1.

FIG. 19 therefore shows the subassembly 25-1 after it has been joined tothe second or mating fitting component 12-1 to a finger tight position.In this position, the retaining member 46-1 is axially forward of aportion of the front ferrule 24-1 that is radially larger than theradial dimension of the distal end 46 a-1. With reference to FIG. 20, weshow just the body 12-1 and the retaining fitting component or nut 14-1after they have been tightened together during pull-up. In this example,we illustrate the parts tightened together during a partial pull-up. Thebody 12-1 includes an axially outboard end 60-1 that will engage theretaining member 46-1 after some predetermined axial displacement of thenut 14-1 relative to the body 12-1. Further tightening of the nut ontothe body causes the outboard end 60-1 to push against the retainingmember 46-1, and in this embodiment, plastically deform and bend theretaining member 46-1 radially outward towards the internal surface 48-1of the nut 14-1. Preferably, although not necessarily, the retainingmember 46-1 may be sufficiently plastically deformed such that it willremain in a bent away position even after the nut 14-1 and body 12-1 maybe subsequently disassembled. In such case, the retaining member 46-1will no longer interfere with the retaining front ferrule 24-1, thusallowing, if so desired, for the nut 14-1 to be axially backed away fromthe body 12-1 even if the ferrules 24-1, 30-1 remain attached to theconduit 18-1.

Although omitted in FIG. 20, axial movement of the nut 14-1 relative tothe body 12-1 causes the ferrules to deform and grip the conduit 18-1(FIG. 19) in a known manner. The retaining structure 40-1 preferably isdesigned so as to not interfere with normal operation and pull-up of theconduit gripping devices onto the conduit to effect grip and seal.

In an alternative embodiment, the retaining member 46-1 may be elasticenough so that it is not necessarily plastically bent away, but ratherwill not prevent the nut 14-1 from being backed off axially from thebody after a partial or complete pull-up. It is contemplated that inthese embodiments, the retaining member 46-1 comprises metal or a stiffnon-metal or plastic material that may plastically deform so as to nolonger interfere with the front ferrule 24-1 after a partial or completepull-up and disassembly of the nut and body. This is to distinguish thematerial of the retaining member from an elastic or elastomeric materialsuch as rubber.

Accordingly, one or more of the embodiments facilitates a mechanism orstructure and method by which one or more ferrules or conduit grippingdevices may be retained with a fitting component as a discontinuouscartridge 25-1, with the retaining structure then being altered duringpull-up (either a complete pull-up or a partial pull-up as needed) sothat the nut 14-1 is released and may subsequently be axially withdrawnor pulled back from the body 12-1. The female nut 14-1 also helps toprotect the ferrules during shipping and handling.

In an exemplary method, one or more conduit gripping devices areretained with a retaining fitting component as a discontinuouscartridge. This discontinuous cartridge forms a first part of a two partfitting assembly. The cartridge is then joined with the second part ofthe fitting assembly and a portion of a conduit. During at least apartial pull-up of the fitting assembly, the conduit gripping devicesbecome attached to the conduit and become disengaged from the retainingfitting component so that the retaining fitting component may be removedfrom the fitting assembly after the partial or complete pull-up whilethe one or more conduit gripping devices remain attached to the conduit.In a more specific embodiment, the method may include the steps ofretaining one or more conduit gripping devices with a retaining fittingcomponent as a discontinuous cartridge, joining the cartridge to asecond fitting component on a conduit to cause the conduit grippingdevices to attach to the conduit, and disengaging the retaining fittingcomponent from the conduit gripping devices so that the retainingfitting component may be removed from the fitting assembly after apartial pull-up while the one or more conduit gripping devices remainattached to the conduit. In still a more specific embodiment, theconduit gripping devices may be snapped into place in the retainingfitting component to form the cartridge.

With reference to FIG. 21, we illustrate an embodiment of a retainingstructure 70-1 that may be used to retain a single conduit grippingdevice with a retaining fitting component. The retaining structure 70-1may be, but need not be, similar to the retaining structure 40-1 of theFIGS. 18-20 embodiment hereinabove. In this example, the retainingstructure 70-1 may include a retaining member 72-1, such as in the formof a bendable tab or pin that interferes with the ferrule 74-1 to retainthe ferrule in the nut 14-1 as a discontinuous subassembly or cartridge.The retaining member 72-1, for example, may interfere with an outersurface 76-1 of the ferrule. The body 12-1 may have an outboard end 60-1that pushes and bends the retaining member 46-1 away so as to releasethe ferrule from the nut for subsequent disassembly, thus allowing thenut 14-1 to be axially moved away from the body even after a partial orcomplete pull-up.

In an alternative embodiment, the body 12-1 need not necessarily contactor bend the retaining member 72-1 away, but rather the inward radialcompression of the ferrule 74-1 during pull-up may be sufficient toallow the ferrule 74-1 to clear the retaining member 72-1 after apartial or complete pull-up.

With reference to FIG. 22, we illustrate another embodiment. In thisembodiment, a retaining structure 40-1 is provided that may be but neednot be the same as described with reference to FIGS. 18-20 above. Inaddition, the front and back ferrules 24-1, 30-1 may comprise ferrulecartridge assembly 100-1 as well, where the ferrules are held togetheras a discrete subassembly before installation into the nut 14-1. Thecartridge ferrule assembly is described in pending United States patentapplication serial no. PCT/US2009/67508 filed on Dec. 10, 2009 forFERRULE ASSEMBLY FOR CONDUIT FITTING noted above.

In the exemplary embodiments of FIGS. 23-32 (wherein the -2 designatoris used to group various alternative embodiments as well as to designatelike components of other embodiments herein as well as distinguishingalternative, different or additional components described with thisgrouping), the front ferrule 24-2 may be conventional in design, if sodesired, so that the first retaining portion 42-2 may simply be realizedin the form of the outer tapered surface 24 a-2 of the front ferrule24-2. Alternatively, the front ferrule may be modified to include astructure or feature (not shown) that will interact with the secondretaining portion 44-2, but for the exemplary embodiments such structureis not needed. In any case, the front ferrule 24-2 will coact with thesecond retaining portion 44-2 so as to retain the ferrule or ferrule settogether with the nut 14-2 as a discrete and discontinuous subassembly25-2.

The second retaining portion 44-2 may be realized in the form of aretaining member 46-2. The retaining member 46-2 may be any generallyannular or ring-like structure or partial ring-like structure thatextends or protrudes generally radially inward to a distance by which aninterior portion or surface 46 a-2 of the retaining member will preventor inhibit the ferrules 24-2, 30-2 from falling out of the retainingfitting component 14-2. The shape and profile of the retaining membermay have a rounded, curved or sloped contour or other shape so as to notscratch or dig into the front ferrule.

As with other embodiments herein, the location, shape, size, length andprofile of the retaining member 46-2 may depend in part on the design ofthe cooperating first retaining portion 42-2 of the front ferrule 24-2.The design of the retaining structure 40-2, including the design of thefirst retaining portion 42-2 and the second retaining portion 44-2, mayalso depend in part on how robust a connection is desired between theretaining fitting component and the conduit gripping devices, in otherwords, the nature of the retention force desired. For example, in someapplications it may be desired to have the ferrules 24-2, 30-2 stronglyand securely retained with the fitting component 14-2 so that theferrules do not fall out or get knocked out during handling, shipping orexposure to other force applying environments, while in otherapplications such a strong retention force may not be needed. As anotherexample, in some applications it may be desired to have the ferrulessnugly held together and retained with the fitting component, while inother applications it may be more desirable to have the ferrulessomewhat loosely held together and retained with the fitting component.These are just a few of the criteria that may be considered whendesigning the retaining structure 40-2. The retaining member 46-2 maycontact the front ferrule 24-2 when the ferrules 24-2, 30-2 and theretaining fitting component 14-2 are installed in the retaining fittingcomponent, or may be axially spaced such that the retaining member onlycontacts the front ferrule 24-2 should the front ferrule drop down intocontact with the retaining member 46-2. Looser retention of the ferrulesin the nut 14-2 may facilitate pull-up of the fitting assembly by notinterfering with centering of the ferrules as the nut 14-2 is initiallyrotated relative to the body 12-2.

The second retaining portion 44-2 may be designed to achieve the desiredretaining force for the subassembly 25-2 prior to assembly with themating fitting component. The second retaining portion 44-2 may alsooptionally be designed to facilitate release of the retaining fittingcomponent from the one or more conduit gripping devices after assemblywith the mating fitting component, for example after or during a partialpull up or a complete pull up of the fitting assembly onto a conduit.

The retaining member 46-2, in cooperation with the taper angle of theouter surface 24 a-2 of the front ferrule, may also be designed suchthat the ferrules 24-2, 30-2 are somewhat loosely retained and may evenhave a slight rattle when the nut 14-2 is gently shaken. This loosenessmay in some applications facilitate final assembly with the second ormating fitting component (in this example the body 12-2), especially inallowing the ferrules to center and align during pull-up of the fittingassembly 10-2. In alternative embodiments, however, the ferrules 24-2,30-2 may be snugly or even tightly retained in the nut 14-2. In anycase, it is contemplated that after the front ferrule 24-2 has beeninserted (the back ferrule being inserted first for a two ferrulefitting) such that the enlarged back end 24 b-2 is axially behind theretaining member 46-2, that the radial inner dimension of the retainingmember 46-2 will be sufficient so as to interfere with the front ferrule24-2 (such as the enlarged back end portion 24 b-2 in the exemplaryembodiment) to prevent or inhibit the front ferrule 24-2 (as well as theback ferrule for a two ferrule fitting assembly) from dropping out ofthe nut 14-2, even if the nut is dropped or otherwise exposed to shockor other adverse forces prior to assembly with the mating fittingcomponent 12-2.

In the exemplary embodiments, the retaining member 46-2 may be realizedin the form of a flexible or compressible ring-like device thatinterferes with the ferrule 24-2 to retain the ferrule in the nut 14-2as a discontinuous subassembly or cartridge 25-2. In the embodiment ofFIG. 23, the retaining member 46-2 may be realized in the form of ano-ring or other resilient elastomeric or plastic or radially flexiblemetal part. The retaining member 46-2 may be captured in a groove orrecess 48-2 formed in the retaining fitting component or nut 14-2. Theretaining member 46-2 may be dimensioned so as to interfere with theradially enlarged rear portion 24 b-2 of the front ferrule 24-2 toprevent the ferrule set (or a single ferrule) from falling out of thenut 14-2. The front ferrule 24-2 may be easily installed by pushing theferrule past the retaining member due to the radial resiliency of theretaining member 46-2. Likewise, after a partial or complete pull-up thenut 14-2 may be easily moved axially back off the fitting assemblybecause the retaining member will not present an excessive resistance tomoving the retaining fitting component back over the retaining member.The retaining member may, but does not have to, contact or engage theretaining conduit gripping device after a partial or complete pull-up.The designer may determine the degree of resistance or interference, ifany, that the retaining member 46-2 presents to separation of theretaining fitting component from the fitting assembly after a completeor partial pull-up.

In the exemplary embodiments, the retaining member 46-2 may exhibit aradial outward force or bias against an interior surface of the recess48-2. The retaining member 46-2 may be continuous or split and need notbe round or of any particular shape. In cases where the retaining memberis an elastomer or shaped ring (as in FIG. 27A hereinbelow), having ahoop strength or outward radial bias against the retaining member 46-2may be beneficial in keeping the retaining member centered. However, forother embodiments, such as the cylindrical ring if FIG. 27B hereinbelow,it may be desirable not to have the ring contact the interior surface ofthe recess 48-2 in the free state as this might prevent radial expansionof the retaining member to allow insertion of the ferrule. Thus, theoptional use of a radial outward load or hoop stress on the retainingmember 46-2 will be determined by the type of materials used and thedesign of the retaining member, as well as the robustness desired forthe discontinuous cartridge.

The retaining member 46-2 may be made of any suitable material,including elastomer, plastic and metal and preferably sturdy enough toretain the ferrules with the nut 14-2 as a cartridge 25-2. Use of ametal retaining member 46-2 allows for all metal fitting assemblies forhigh temperature applications or use with fluids that may damage anelastomer or plastic. Suitable metals may include but are not limited tostainless steel, brass, copper, steel, metal wire and so on to name justa few of the many available materials.

Axial movement of the nut 14-2 relative to the body 12-2 causes theferrules to deform and grip the conduit 18-2 in a known manner. Theretaining structure 40-2 preferably is designed so as to not interferewith normal operation and pull-up of the conduit gripping devices ontothe conduit to effect grip and seal, or with remakes of the fitting.

For embodiments that use a retaining member 46-2 in the form of acompressed ring, it will be appreciated that in many uses the ring maylikely be fairly stiff while in the cartridge subassembly as well as inthe finger-tight position. This stiffness may be used to assure a robustsubassembly that does not come apart too easily (as determined by thedesigner) during handling and shipping.

Use of the discontinuous cartridge 25-2 facilitates providing ferrulesets to the end user in which the ferrules and nuts are properly matchedat the manufacturer. This can significantly simplify inventory controland reduce final assembly time. The embodiments herein also allow for acartridge design in which the retaining fitting component may be usedfor fitting assemblies that do not need or have the retaining member46-2. In other words, the cartridge designs herein use a nut orretaining fitting component that is backwards compatible with fittingassemblies that the end user may not require with a retaining structure.The cartridge design also may be realized using ferrule sets that do notrequire modification. Therefore, the cartridge concepts herein may beoptionally provided for an end user without having to manufacture nutsor ferrules with different geometry and operation or performance. Thisallows the convenience of manufacturing and selling fitting componentsand ferrules as separate parts regardless of the end use of suchindividual parts, either for a cartridge use or a non-cartridge use.

With reference to FIG. 24, we illustrate an alternative embodiment of acartridge nut assembly. In this embodiment, the nut 14-2, body 12-2 andretaining structure 40-2 and operation may be but need not be the sameas described hereinabove with reference to FIG. 23. Therefore, we uselike reference numerals for like parts in the drawings. The notabledifference in this embodiment is that we incorporate a ferrule cartridge70-2 that provides a ferrule set of a front ferrule 72-2 and a backferrule 74-2 that may be connected together as a discrete subassembly orcartridge before the ferrules are assemble with the retaining nut 14-2.The back ferrule 74-2 may be but need not be the same as the backferrule 30-2 in the FIG. 23 embodiment. The front ferrule 72-2 mayinclude a retaining structure 76-2 in the form of an extension or tang78-2 that provides a socket or recess 80-2. The back ferrule frontportion 74 a-2 may be snapped into this recess 80-2 so as to connect theferrules together as a ferrule cartridge. The cartridge nut retainingstructure 40-2 may operate in the same manner as described hereinabovewith respect to FIG. 23. The ferrule cartridge design is fully describedin pending United States patent application serial no. PCT/US2009/67508filed on Dec. 10, 2009 for FERRULE ASSEMBLY FOR CONDUIT FITTING, thenentire disclosure of which is fully incorporated herein by reference.

With reference to FIGS. 25-28 we illustrate another embodiment of afitting assembly 100-2 that uses a cartridge nut 25-2 arrangement. Mostof the parts of the fitting assembly 100-2 may be though need not be thesame as the embodiment of FIG. 23, and like parts are given likereference numerals and the description thereof need not be repeated. Inthe example of FIGS. 25-28, rather than an elastomer or plasticretaining member as part of the retaining structure 40-2, we use aretaining member 102-2 in the form of a thin metal wire-like ring. Thisretaining ring 102-2 may comprise any suitable metal, including but notlimited to stainless steel.

The retaining ring 102-2 preferably is dimensioned so that an interiorsurface portion 104-2 (FIG. 26, note in FIG. 26 we omit the conduit 18-2for clarity) will interfere with the first retaining portion 42-2 of theretaining structure 40-2, which in this example the first retainingportion 42-2 may be realized in the form of the outer conical surface 24b-2 of the front ferrule 24-2. The interference between the retainingring 102-2 and the front ferrule 24-2 may be selected to produce thedesired robustness of the connection of the ferrules 24-2, 30-2 in thenut 14-2 as described herein above. Preferably, the retaining ring 102-2is provided with sufficient radial give or flexibility so that theferrules may be pushed past the retaining ring 102-2 to assemble theparts as a cartridge 25-2.

A recess or groove 106-2 is provided for locating the retaining ring102-2 at a desired axial location. When the fitting is in thefinger-tight position as illustrated, or when the cartridge 25-2 isassembled as a separate discrete assembly, the retaining ring expandssomewhat into the recess 106-2 to be retained therein, such that anouter surface portion 108-2 of the retaining ring may interfere with aportion 110-2 of the recess 106-2 so as to be retained in the recess106-2 even if the front ferrule 24-2 is knocked against or pushedagainst the retaining ring 102-2 during handling or shipment.

FIGS. 27A and 27B illustrate to examples of a retaining ring 102-2. Inboth cases the retaining ring 102-2 may be a split ring as at 112-2, butcontinuous rings may alternatively be used. The split ring concept formetal allows for increased control of the radial flexibility of thering. The FIG. 27A embodiment may be hexagonal shaped, although otherpolygonal shapes or non-polygonal shapes may be used as needed, and theFIG. 27B embodiment is a simple circular shape. The hexagonal shape orother non-circular profile may be used to reduce the number of directcontact locations or points 114-2 between the retaining ring 102-2 andthe front ferrule 24-2. This may reduce the amount of friction betweenthe ring and the front ferrule during assembly, as well as reducing thefriction between these parts during disassembly to facilitate axiallybacking the nut 14-2 away from the body 12-2. Moreover, a non-circularprofile such as illustrated in FIG. 27A facilitates use of a retainingring 102-2 that may optionally contact the outer diameter of the recess106-2 at discrete locations to help center the ring 102-2, while at thesame time providing a number of direct contact locations for retainingthe ferrules.

FIG. 28 illustrates the fitting in a pull-up position. As with theembodiment of FIG. 25, note that the retaining ring 102-2 does notinterfere with operation of the ferrules 24-2, 30-2 during pull-up.

With reference to FIG. 29, we illustrate an alternative embodiment of acartridge nut assembly. In this embodiment, the nut 14-2, body 12-2 andretaining structure 40-2 and operation may be but need not be the sameas described hereinabove with reference to FIGS. 25-28. Therefore, weuse like reference numerals for like parts in the drawings. The notabledifference in this embodiment is that we incorporate a ferrule cartridge150-2 that provides a ferrule set of a front ferrule 152-2 and a backferrule 154-2 that may be connected together as a discrete subassemblyor cartridge before the ferrules are assemble with the retaining nut14-2. The back ferrule 154-2 may be but need not be the same as the backferrule 30-2 in the FIGS. 23-28 embodiments. The front ferrule 152-2 mayinclude a retaining structure 156-2 in the form of an extension or tang158-2 that provides a socket or recess 160-2. The back ferrule frontportion 154 a-2 may be snapped into this recess 160-2 so as to connectthe ferrules together as a ferrule cartridge. The cartridge nutretaining structure 40-2 may operate in the same manner as describedhereinabove with respect to FIGS. 23-28.

It will be noted that the front ferrule 152-2 has a different geometryfrom the front ferrules of the embodiments of FIGS. 23-28 hereinabove.In particular, the front ferrule 152-2 may optionally include a back-endflange 162-2. This flange 162-2 has an outer diameter that allows for aninterference between the front ferrule 152-2 and the retaining ring102-2 so as to hold the ferrules 152-2, 154-2 and the nut 14-2 togetheras a discontinuous cartridge 25-2. The flange 162-2 may be used toprovide inboard and outboard surfaces 164-2, 166-2 that contact theretaining ring 120-2 during assembly and disassembly. In this example,the contacting surfaces 164-2, 166-2 are radii but other geometries maybe used as needed. Also as illustrated, the inboard and outboardsurfaces 164-2, 166-2 may be identical in shape and also may blend tothe same cylindrical outer diameter of the flange 162-2 so that thefront ferrule 152-2 can snap through or otherwise move past theretaining ring 120-2 with about equal force, whether the action is aninitial assembly, a disassembly or a reassembly for remake. The flange162-2 also may be axially dimensioned so as to prevent a portion of thefront ferrule 152-2 from falling into the recess 106-2.

With reference to FIGS. 30-32 we illustrate another embodiment of aretaining member for providing a discontinuous cartridge assembly. FIG.30 shows a partial cutaway of a female nut 180-2 that can be assembledwith a body (not shown). A ferrule 184-2 is shown retained in the nut180-2 using a retaining member in the form of a retaining ring 186-2.The ferrule 184-2 may be a single ferrule, the front ferrule of a twoferrule fitting, or a back ferrule of a two ferrule fitting,particularly when a ferrule cartridge concept is also used.

FIGS. 31 and 32 illustrate the retaining ring 186-2 in more detail, andis an alternative configuration to the rings shown in FIGS. 27A and 27B,for example. The ferrule 184-2 shape may be conventional, if so desired,or alternatively any shape that will cooperate with the retaining ring186-2 to provide a cartridge nut assembly 25-2. The retaining ring 186-2optionally includes one or more radial outward tabs 188-2 that arereceived in a groove 190-2 formed in the nut 180-2. The retaining ring186-2 may be push inserted into the groove 190-2, or the radial outwardtabs may be formed so as to allow the retaining ring 186-2 to bethreaded into the nut 180-2 via the female threads 192-2 if so desired.Preferably, the radial outer tabs are flexible enough to permit assemblyof the retaining ring 186-2 with the nut 180-2 but sufficiently rigid toprovide a robust cartridge assembly. We show three radial outward 188-2evenly spaced about the circumference of the retaining ring body, butmore or less tabs may be used with different spacing if so required. Inan exemplary embodiment, each tab 188-2 may subtend about ten degreesarc although other sizes may be used as needed. The retaining ring maycomprise any suitable material, including but not limited to a robustplastic or metal such as stainless steel, but may also be an elastomeror softer polymer. The retaining ring 186-2 may be formed rather thin,perhaps only ten thousandths for example, particularly if the ring ismade of a fairly stiff material. The material and geometry of theretaining ring will be selected based in part on the desired robustnessneeded for the cartridge application.

The retaining ring 186-2 further is provided with one or more optionalradial inward tabs 194-2 that engage or interfere with the ferrule 184-2when the ferrule 184-2 is inserted through the retaining ring 186-2. Theferrule 184-2 may include a flange (such as in the embodiment of FIG. 29herein) or enlarged back end (such as the embodiment of FIG. 23 herein)that snaps through the retaining ring 186-2. The radial inward tabs194-2 then will prevent the ferrule or ferrules from falling out of thecartridge assembly 25-2. During pull-up the retaining ring 186-2 travelswith the nut 180-2. Since the nut 180-2 travels axially further than theferrule 184-2 during pull-up, the retaining ring 186-2 will notinterfere with the function of the ferrule. In this embodiment, it iscontemplated that upon disassembly the retaining ring will remain withthe nut 180-2 so as to reengage with the ferrule 184-2 (or a replacementferrule as the case may be) for remakes. Since the ferrule 184-2typically will be compressed against the conduit after a pull-up, havingthe retaining ring 186-2 remain with the nut 180-2 allows the nut 180-2to be axially withdrawn or pulled back from the body.

When the ferrule 184-2 is a front ferrule of a two ferrule fitting, thefront ferrule will also retain the back ferrule in the cartridgeassembly. Alternatively, however, even with the ferrule 184-2 being afront ferrule, the ferrule cartridge concept described hereinabove mayalso be used.

In the exemplary embodiments of FIGS. 33-42 (wherein the -3 designatoris used to group various alternative embodiments as well as to designatelike components of other embodiments herein as well as distinguishingalternative, different or additional components described with thisgrouping), the front ferrule 24-3 may be conventional in design, if sodesired, so that the first retaining portion 42-3 may simply be realizedin the form of the outer tapered surface 24 a-3 of the front ferrule24-3. Alternatively, the front ferrule may be modified to include astructure or feature (not shown) that will interact with the secondretaining portion 44-3, but for the exemplary embodiments such structureis not needed. In any case, the front ferrule 24-3 will coact with thesecond retaining portion 44-3 so as to retain the ferrule or ferrule settogether with the nut 14-3 as a discrete and discontinuous subassembly25-3.

The second retaining portion 44-3 may be realized in the form of aretaining member 46-3. The retaining member 46-3 may be any generallyannular or ring-like structure or partial ring-like structure thatextends or protrudes generally radially inward to a distance by which adistal portion 46 a-3 of the retaining member will prevent or inhibitthe ferrules 24-3, 30-3 from falling out of the retaining fittingcomponent 14-3. However, alternatively the retaining member 46-3 mayprotrude inwardly other than just radially. A distal portion 46 a-3 mayalso alternatively have a rounded, curved or sloped contour or othershape so as to not scratch or dig into the front ferrule. Although theretaining member 46-3 illustrated herein has a rectangular cross-sectionand extended axial length, the retaining member 46-3 may alternativelyhave a round or other cross-sectional shape with a narrow diameter oraxial dimension, such as a wire, for example.

The retaining member 46-3 may have a retaining position and a release ordisengage position. In the retaining position the conduit grippingdevices and the retaining fitting component form the discontinuouscartridge 25-3. In the release position, the retaining fitting componentis separable from the conduit gripping devices. Preferably, theretaining member is in the release position after a partial or completepull-up but not in a finger-tight position. For example, the retainingmember 46-3 may be a structure that is movable relative to the retainingcomponent so as to have a first axial position at which the retainingmember 46-3 interferes with the retaining conduit gripping device (thefront ferrule 24-3 in the embodiment of FIGS. 33-35), and a second axialposition at which the retaining member 46-3 does not adversely interferewith the retaining conduit gripping device.

By “adversely interfere” is meant that the retaining member no longersignificantly resists separation of the retaining fitting component andthe one or more conduit gripping devices, and also does not present anobstruction or otherwise affect operation of the conduit grippingdevices during pull up, or with remakes. But, the retaining member may,but does not have to, contact or engage the retaining fitting componentin the release position. The designer may determine the degree ofresistance or interference, if any, that the retaining member presentsto separation of the retaining fitting component from the fittingassembly after a complete or partial pull-up. This feature of a secondposition in which the retaining member 46-3 does not adversely interferewith the retaining conduit gripping device may optionally also beutilized in other of the embodiments described herein.

In other embodiments, the retaining member 46-3 may also exhibit a firstradial position and a second radial position at the first and secondaxial positions respectively. For example, the innermost radialdimension of the retaining member 46-3 at the second axial position maybe sufficiently greater than the innermost radial dimension at the firstaxial position so as not to adversely interfere with the retainingconduit gripping device. In still other embodiments, the retainingmember 46-3 may have first and second radial positions at a single axialposition.

With reference to FIGS. 33-35 herein, the retaining position, forexample, a first axial position and/or a first radial position, may beused for the stand alone cartridge 25-3, and the retaining member 46-3may remain in the retaining position (axially, radially or both) whenthe fitting assembly 10-3 is in the finger tight position illustrated inFIG. 33. As a result of, for example, a partial pull-up, the retainingmember 46-3 assumes a second axial position. In other words, during apartial or complete pull-up the retaining member 46-3 may shift axially,radially or both relative to the retaining fitting component to therelease or disengage position. In this exemplary embodiment, theretaining member 46-3 moves axially and radially relative to theretaining fitting component to the release or disengage position of FIG.35, as understood in comparing FIG. 35 with the retaining position ofFIG. 33.

In the exemplary embodiment of FIGS. 33-35, the retaining member 46-3may be realized in the form of a snap ring or other ring like memberthat preferably exhibits a radial outward force or bias against aninterior surface of the nut 14-3 in the retaining position. The ring maybe continuous or split and need not be round or of any particular shape.

The retaining member 46-3 may be made of any suitable material,including elastomer, plastic and metal and preferably sturdy enough toretain the ferrules with the nut 14-3 as a cartridge 25-3. Use of ametal retaining member 46-3 allows for all metal fitting assemblies forhigh temperature applications or use with fluids that may damage anelastomer or plastic. Suitable metals may include but are not limited tostainless steel, brass, copper, steel and so on to name just a few ofthe many available materials.

The retaining fitting component or nut 14-3 may have a first recess orpocket 48-3 formed in an interior surface of the nut 14-3 that receivesthe retaining member 46-3 and axially locates the retaining position.The first recess 48-3 may be formed in the interior cylindrical wall50-3 of the nut 14-3. After the ferrule set 24-3, 30-3 has been insertedinto the nut 14-3, the retaining member 46-3 is inserted so as to snapinto the first radial recess 48-3. The radial depth of the first recess48-3 along with the dimensions of the retaining member 46-3 may beselected so that the retaining member 46-3 interferes with and inhibitsthe ferrule set (ferrules 24-3, 30-3) from falling out of the nut 14-3.The outward spring bias of the retaining member 46-3 along with anoptional backing shoulder 52-3 may be used to help keep the retainingmember 46-3 in the first recess 48-3.

The retaining fitting component or nut 14-3 may also include a secondrecess 54-3 that is located at an axial position that is different thanthe axial position of the first radial recess 48-3. The second recess54-3 axially locates the release or disengage position and may be formedin an interior surface of the nut 14-3. The second recess 54-3 may beaxially adjacent the first radial recess 48-3 as in FIGS. 33-35, or maybe further axially spaced therefrom as needed. The second recess 54-3preferably, although not necessarily, has a greater radial dimensionthan the first radial recess 48-3 so that when the retaining member 46-3moves into the second radial recess 54-3, it expands radially outwardlyas shown in FIG. 35. The second radial recess 54-3 thus axially locatesthe release position. The radial depth of the second radial recess 54-3may be chosen so that when the retaining member 46-3 is located therein,the retaining member no longer adversely interferes with the conduitgripping devices 24-3, 30-3.

FIGS. 33 and 34 show the subassembly 25-3 after it has been joined tothe second or mating fitting component 12-3 to a finger tight position.In this position, the retaining member 46-3 is axially forward (inboard)of a portion 24 b-3 of the front ferrule 24-3 that is radially largerthan the innermost radial dimension of the distal portion 46 a-3. Withreference to FIG. 35, we show the body 12-3, the conduit grippingdevices 24-3,30-3, and the retaining fitting component or nut 14-3 afterthey have been tightened together during pull-up. In this example, weillustrate the parts tightened together after a complete pull-up. Thebody 12-3 includes an axially outboard end 60-3 that will engage theretaining member 46-3 after some predetermined axial displacement of thenut 14-3 relative to the body 12-3. Further tightening of the nut ontothe body causes the outboard end 60-3 to push against the retainingmember 46-3, and in this embodiment, push or displace the retainingmember 46-3 axially relative to the nut 14-3 towards and into the secondradial recess 54-3 of the nut 14-3. In this release position, theretaining member 46-3 will no longer adversely interfere with theretaining front ferrule 24-3, thus allowing, if so desired, for the nut14-3 to be axially backed away from the body 12-3 even if the ferrules24-3, 30-3 remain attached to the conduit 18-3.

Typically, fittings are pulled-up by holding the body 12-3 rotationallyfixed and using a wrench to rotate the nut 14-3 relative to the body12-3. This causes an axially advance of the nut onto the body. But thisrelative axial advance of the nut and body together may also be effectedby holding the nut and rotating the body or rotating both the nut andthe body. Therefore, for purposes of this disclosure we consider the“movement” of the retaining member from the retaining position to therelease position as being a relative movement between the retainingmember 46 and the nut 14-3. This can be viewed as the body end 60-3“pushing” on the retaining member 46-3, or simply abutting the retainingmember 46-3 as the nut advances. Regardless of how the nut and body aretightened together, the retaining member 46-3 will exhibit an axialand/or radial displacement relative to the retaining fitting componentso as to “move” from the retaining position to the release position.

The axial position of the second recess 54-3 may be used to determine atwhat point during a pull-up procedure the retaining member 46-3disengages from the front ferrule 24-3. In other words, the axialposition of the second recess may be selected so as to allow theretaining member 46-3 to disengage during a partial pull-up or closer tocompletion of a completed pull-up. The retaining member may also releaseafter a pre-swaging operation.

Axial movement of the nut 14-3 relative to the body 12-3 causes theferrules to deform and grip the conduit 18-3 in a known manner. Theretaining structure 40-3 preferably is designed so as to not interferewith normal operation and pull-up of the conduit gripping devices ontothe conduit to effect grip and seal, or with remakes of the fitting.

The axial dimension of the first radial recess 48-3 may be chosen inconcert with the amount of relative axial displacement of the nut 14-3and the body 12-3 to determine at what point during pull-up theretaining member 46-3 is transposed to the release position by beingmoved into the second radial recess 54-3. For example, it may be desiredin some embodiments to have the retaining member 46-3 be displaced tothe release position prior to completion of a pull-up operation. Forexample, it may be desired to have the retaining member release after apartial pull-up or after a pre-swage operation.

Accordingly, one or more of the present inventions facilitates amechanism or structure and method by which one or more ferrules orconduit gripping devices may be retained with a fitting component as adiscontinuous cartridge 25-3, with the retaining structure then beingaxially moved, radially moved or both during pull-up (either a completepull-up or a partial pull-up as needed) so that the retaining structureis released from the conduit gripping devices to allow the nut 14-3 tobe subsequently axially withdrawn or pulled back from the body 12-3.

For embodiments that use a retaining member 46-3 in the form of acompressed ring, it will be appreciated that in many uses the ring maylikely be highly compressed while in the cartridge subassembly as wellas in the finger-tight position. This compression may be used to assurea robust subassembly that does not come apart too easily (as determinedby the designer) during handling and shipping. It can therefore beexpected that when the retaining member shifts into the releaseposition, that the retaining member 46-3 may snap out into the secondrecess 54-3 with sufficient impact as to produce an audible “click”.This audible feedback may alert the assembler directly that theretaining member has released, or sensors may be used (such as, forexample, recorders, transmitters and light indicators) to indicatesufficient pull-up to the release position.

Use of the discontinuous cartridge 25-3 facilitates providing ferrulesets to the end user in which the ferrules and nuts are properly matchedat the manufacturer. This can significantly simplify inventory controland reduce final assembly time. The embodiments herein also allow for acartridge design in which the retaining fitting component may be usedfor fitting assemblies that do not need or have the retaining member46-3. In other words, the cartridge designs herein use a nut orretaining fitting component that is backwards compatible with fittingassemblies that the end user may not require with a retaining structure.The cartridge design also may be realized using ferrule sets that do notrequire modification. Therefore, the cartridge concepts herein may beoptionally provided for an end user without having to manufacture nutsor ferrules with different geometry and operation or performance. Thisallows the convenience of manufacturing and selling fitting componentsand ferrules as separate parts regardless of the end use of suchindividual parts, either for a cartridge use or a non-cartridge use.

In an exemplary method, one or more conduit gripping devices areretained with a retaining fitting component as a discontinuouscartridge. This discontinuous cartridge forms a first part of a two partfitting assembly. The cartridge is then joined with the second part ofthe fitting assembly and a portion of a conduit. During at least apartial pull-up of the fitting assembly, the conduit gripping devicesbecome attached to the conduit and become disengaged from the retainingstructure of the retaining fitting component so that the retainingfitting component may be removed from the fitting assembly after thepartial or complete pull-up while the one or more conduit grippingdevices remain attached to the conduit. In a more specific embodiment,the method may include the steps of retaining one or more conduitgripping devices with a retaining fitting component as a discontinuouscartridge, joining the cartridge to a second fitting component on aconduit to cause the conduit gripping devices to attach to the conduit,and disengaging the retaining fitting component from the conduitgripping devices so that the retaining fitting component may be removedfrom the fitting assembly after a partial pull-up while the one or moreconduit gripping devices remain attached to the conduit. In still a morespecific embodiment, the conduit gripping devices may be retained in theretaining fitting component to form the cartridge by a retaining memberhaving a retaining position and a release position. In the releaseposition, the retaining member does not interfere with axialdisplacement of the retaining fitting component after a complete oralternatively partial pull-up.

With reference to FIGS. 36 and 37, we illustrate an alternativeembodiment of a cartridge nut assembly. In this embodiment, the nut14-3, body 12-3 and retaining structure 40-3 and operation may be butneed not be the same as described hereinabove with reference to FIGS.33-35. Therefore, we use like reference numerals for like parts in thedrawings. The notable difference in this embodiment is that weincorporate a ferrule cartridge 70-3 that provides a ferrule set of afront ferrule 72-3 and a back ferrule 74-3 that may be connectedtogether as a discrete subassembly or cartridge before the ferrules areassemble with the retaining nut 14-3. The back ferrule 74-3 may be butneed not be the same as the back ferrule 30-3 in the FIGS. 33-35embodiment. The front ferrule 72-3 may include a retaining structure76-3 in the form of an extension or tang 78-3 that provides a socket orrecess 80-3. The back ferrule front portion 74 a-3 may be snapped intothis recess 80-3 so as to connect the ferrules together as a ferrulecartridge. Note from the pulled-up position in FIG. 37, the ferrulecartridge retaining structure has released the front and back ferrules.The cartridge nut retaining structure 40-3 has operated in the samemanner as described hereinabove with respect to FIGS. 33-35. The ferrulecartridge design is fully described in pending United States patentapplication serial no. PCT/US2009/67508 filed on Dec. 10, 2009 forFERRULE ASSEMBLY FOR CONDUIT FITTING, noted above.

With reference to FIGS. 38 and 39, in an alternative embodiment, we usethe retaining conduit gripping device, in this example the frontferrule, to help position and hold the retaining member relative to theretaining fitting component during pull-up. More specifically, the frontferrule may be used to control the axial position of the retainingmember during pull-up by having structure that causes the retainingmember to be axially fixed with the front ferrule at least to the pointof the second axial position (the release position). This avoids havingto establish contact between the mating fitting component and theretaining member in order for the retaining member to move to therelease position, and utilizes the observation that the nut advancesaxially onto the body faster than the front ferrule axially advancesrelative to the body.

Accordingly, a retaining structure 100-3 may be provided having a firstretaining portion 102-3 associated with the retaining conduit grippingdevice 104-3, in this case the front ferrule, and a second retainingportion 106-3 associated with the retaining fitting component 108-3, inthis case the female threaded nut. A retaining member 110-3 is providedin the form of an annular device such as a ring or wire made of suitablematerial to provide a robust retention of the ferrule or ferrule set inthe nut as a cartridge or subassembly. In the preferred embodiment, theretaining member comprises a rather stiff metal spring ring or wire thatwill have sufficient hoop strength to retain the ferrule or ferrule setwith the nut as a cartridge.

Referring to FIG. 39 (FIG. 39 illustrates the cartridge nut arrangementassembled with the body 12-3 in a finger-tight position), the retainingstructure 100-3 may be realized in the form of a first groove or recess112-3 formed in the tapered outer wall 114-3 of the front ferrule 104-3.This first recess 112-3 receives an inner portion of the retainingmember 110-3, and presents a radial flange 116-3 at the rearward portionof the front ferrule 114-3 having a wall portion 118-3 that preferablycontacts the retaining member 110-3 when the retaining member 110-3 isin the retaining position (such as illustrated in FIG. 39).

The retaining fitting component 108-3, in this case the female threadednut, includes a second recess 120-3 formed in an interior surface of thenut, which in some embodiments may function similar to a detentmechanism. The second recess 120-3 axially locates the retainingposition for the retaining member 110-3. During assembly, the retainingmember 110-3 may be held radially compressed in the first recess 112-3until the ferrules are in position within the nut 108-3. The retainingmember 110-3 is then partially released to expand and engage the secondrecess 120-3. This is the retaining position illustrated in FIG. 39. Thesecond recess 120-3 may be used to help keep the retaining member 110-3in the retaining position during normal handling so that the retainingmember 110-3 does not pop out of the front ferrule recess 112-3 andrelease from the front ferrule 104-3. When the ferrule or ferrule set isinstalled in the nut as a cartridge, as well as when the fitting is in afinger-tight position, the first recess 112-3 is preferably generallyaxially aligned with the second recess 120-3 so that the retainingmember is held in compression with strong hoop strength as needed tohold the ferrules with the nut.

The retaining fitting component 108-3 includes a third recess 122-3.This third recess 122-3 is located at an axial position that isdifferent than the axial position of the second radial recess 120-3. Thethird recess 122-3 axially locates the release or disengage position andmay be formed in an interior surface of the nut 108-3. The third recess122-3 may be axially adjacent the second recess 120-3 as in FIG. 39, ormay be further axially spaced therefrom as needed. The third recess122-3 preferably, although not necessarily, has a sufficiently greaterradial dimension than the second recess 120-3 so that when the retainingmember 110-3 moves into the third recess 122-3, it expands radiallyoutwardly as shown in FIG. 40. The third recess 122-3 thus axiallylocates the release position. The radial depth of the third recess 122-3may be chosen so that when the retaining member 110-3 is locatedtherein, the retaining member no longer adversely interferes with theconduit gripping devices.

By comparing FIGS. 39 and 40, during a partial or complete pull-up, thenut 108-3 advances axially further for each relative turn of the nut andbody than does the front ferrule 104-3. As the nut 108-3 axiallyadvances relative to the body 12-3, the retaining member 110-3 isaxially positioned with the front ferrule. When the first recess 112-3becomes axially aligned with the third recess 122-3, the retainingmember will snap or otherwise move into the third recess 122-3 as theflange 116-3 moves past the transition region 124-3 between the secondand third recesses 120-3, 122-3. As the flange 116-3 begins to move pastthe transition region 124-3, a gap or opening 121-3 forms between thefront ferrule 104-3 and the interior surfaces of the nut 108-3. Oncethis gap 121-3 becomes large enough, the retaining member 110-3 movesinto the third recess 122-3. A wall portion 112 a-3 of the first recess112-3 may be used to move the retaining member 110-3 into the thirdrecess 122-3. Since the retaining member 110-3 goes to a lower energycondition (less hoop stress) in the third recess 122-3, the retainingmember will also tend to snap into the third recess. Note that becauseof this transition of higher energy to lower energy of the retainingmember between the first and second axial positions, the flange 116-3helps to prevent the retaining member from moving into the thirds recess122-3 too soon, because the flange 116-3 at least partially blocks orobstructs the third recess 122-3.

Once the retaining member 110-3 is positioned at the release position,the retaining member 110-3 no longer adversely interferes with theretaining conduit gripping member 104-3. The facing wall 118-3 may helpto maintain the stability of the retaining member 110-3 during pull-upas the nut 108-3 axially advances relative to the retaining member110-3. The radial flange 116-3 may also be used to present a surface 116a-3 that sufficiently blocks the third recess 122-3 until such partialor complete pull-up as desired to allow the retaining member 110-3 tomove into the third recess 122-3. This may be used to prevent theretaining member 110-3 from accidentally releasing into the third recess122-3 during normal handling of the cartridge assembly or when thecartridge is assembled with the body 12-3 in the finger-tight position.Thus, the front ferrule 104-3 may be thought of in terms of being keyedto the retaining fitting component 108-3 in the sense that the relativeaxial position of the ferrule 104-3 with the nut 108-3 will determinewhen the retaining member 110-3 axially shifts to the release or secondaxial position.

By appropriate sizing and location of the first recess 112-3, the frontferrule 104-3 may be used in a fitting that utilizes the retainingfeature, or a fitting that does not use the retaining feature, since theferrule will still perform as needed in a non-cartridge design.

Note that in the embodiment of FIGS. 38-40 we illustrate the ferrule setas a ferrule cartridge assembly 126-3 utilizing the front ferrule 104-3and a back ferrule 128-3, held together with a retaining structure130-3. This use of the ferrule cartridge is optional as in the aboveembodiments herein, and may be but need not be, similar in design to theferrule cartridge 70-3 (FIG. 36) and the ferrule cartridge conceptsdisclosed in the above-referenced pending patent application.

With reference to FIGS. 41 and 42 we illustrate another embodiment. Inthis embodiment, the retaining fitting component 108-3 may be but neednot be similar to the nut 108-3 of the FIGS. 38-40 embodiment, theretaining member 110-3 may be but need not be the same as well, and thesame reference numerals are used for like features. The notabledifference between this embodiment and the embodiment of FIGS. 38-40 isthe front ferrule 132-3. In this design, the front ferrule 132-3includes a first recess 134-3 in the outer wall 136-3 of the ferrule.This provides a first radial flange 138-3 having a wall portion 140-3that preferably can contact the retaining member 110-3 when theretaining member 110-3 is in the retaining position. This first radialflange 138-3 presents a surface 138 a-3 that also may be used tosufficiently block the third recess 122-3 so as to prevent the retainingmember 110-3 from moving into the third recess 122-3 during normalhandling of the cartridge assembly or in the finger-tight position ofthe fitting assembly. Moreover, a second radial flange 142-3 may befurther provided on the inboard side of the first recess 134-3. Thissecond radial flange 142-3 provides an axially lengthened major diameteron the front ferrule 132-3, thus providing more material for the frontferrule as compared to the embodiment of FIGS. 38-40. This addedmaterial assures no loss of tensile hoop spring load when the frontferrule and fitting have been completely pulled up. The lengthened majordiameter also presents a surface 144-3 that bridges or otherwise atleast partially obstructs the second recess 120-3 upon complete pull-upto prevent the front ferrule 132-3 from adversely engaging the secondrecess 120-3 during subsequent remakes and reassembly.

As with the embodiment of FIGS. 38-40, the embodiment of FIGS. 41-42illustrate optional use of the ferrule cartridge configuration.

In the exemplary embodiments of FIGS. 43-49 (wherein the -4 designatoris used to group various alternative embodiments as well as to designatelike components of other embodiments herein as well as distinguishingalternative, different or additional components described with thisgrouping), the retaining structure 40-4 may be realized in manydifferent ways, but in general may include a first retaining portion42-4 that may be associated with at least one of the conduit grippingdevices, and a second retaining portion 44-4 that may be associated withthe fitting component being used to form the subassembly 25-4. In thepresent disclosure we show embodiments of two concepts, a first conceptin which the second retaining portion 44-4 is a discrete separate partthat is attachable or connectable with the retaining fitting component,and a second concept in which the second retaining portion 44-4 isintegral with the retaining fitting component.

In the case of two or more conduit gripping devices or a ferrule set,the embodiments of a cartridge nut herein derive additional benefit forfitting assembly processes when used in combination with a ferrulecartridge concept, because the cartridge nut concepts herein relate to aretaining structure for holding the back or outboard ferrule to theretaining fitting component. In alternative embodiments, however, itwill be feasible to have the retaining structure hold the front orinboard ferrule to the fitting component, with the ferrule cartridgefeature thus being optional, or may hold a single conduit grippingdevice or may hold only the outboard conduit gripping device.

Although not limiting the scope of the present inventions, the exemplaryfitting design of FIGS. 43-49 is well known and commercially availablefrom Swagelok Company, Solon, Ohio, except as follows. In the exemplaryembodiments herein that utilize two or more ferrules or additional partswith one or more ferrules, the ferrules include a ferrule cartridgefeature or retaining structure R that allows the ferrules to beassembled together as a discrete unit. The ferrule cartridge design isfully described in pending United States patent application serial no.PCT/US2009/67508 filed on Dec. 10, 2009 for FERRULE ASSEMBLY FOR CONDUITFITTING, noted above. The ferrule cartridge retaining feature Rcooperates with the retaining feature described hereinbelow so as toretain two ferrules with the retaining fitting component if so desired.However, the retaining feature described herein may also be used toretain a single conduit gripping device with the retaining fittingcomponent, or may be used to retain only one of two ferrules (such asthe back ferrule 30-4 for example) in a two ferrule fitting, or otherferrule cartridge retaining structures may be used as needed. Therefore,the retaining feature and concepts herein are not limited in any mannerto the disclosed use with the ferrule cartridge retaining structure R.Moreover, other ferrule cartridge retaining structures may alternativelybe used, including using an adhesive to hold the ferrules together.

In the exemplary embodiments herein, the back ferrule 30-4 may beconventional in design, if so desired, so that the first retainingportion 42-4 may simply be realized in the form of the internal recess39 a-4 of the back ferrule 30-4. For back ferrules or single ferrulesthat do not have such a recess, a notch or other relief or structure maybe formed or otherwise provided, provided that such change does notadversely affect form, fit and function of that ferrule or the fitting.

Alternatively, the front ferrule may be modified to include a structureor feature (not shown) that will interact with the second retainingportion 44-4, but for the exemplary embodiments such structure is notused. For example, a notch or relief may be formed in the insidecylindrical wall of the front ferrule provided such a notch or reliefdoes not adversely affect the form, fit and function of the frontferrule, In such an example, for instance, the second retaining portion44-4 may wrap around the outside of the back ferrule 30-4 so as not tointerfere with the conduit gripping function of the back ferrule duringpull-up. The second retaining portion 44 may extend to the front ferruleto provide the cartridge nut assembly.

The fitting parts 12-4, 14-4, 24-4 and 30-4 illustrated herein, otherthan with the ferrule cartridge retaining structure R and the retainingfeature of the present disclosure, are also further described in anumber of issued and pending patent applications, including U.S. Pat.Nos. 5,882,050 and 6,629,708 which are fully incorporated herein byreference. The fittings of FIGS. 43-48 herein may operate as describedin such patents, but are modified as described herein to provide adiscontinuous cartridge, subassembly or preassembly for retaining atleast one conduit gripping device with one of the fitting components, asset forth below. It is intended that the retaining structures for theferrule cartridge concept and the cartridge nut concept do not alter theform, fit and function of the basic fitting design and operation.

In this exemplary embodiment, two conduit gripping devices are retainedwith the female threaded nut 14-4 as a discontinuous cartridge 25-4, butalternative embodiments may be realized with a single conduit grippingdevice or more than two gripping devices with or without additionalparts, or with male threaded nuts, or any combination thereof. For thecase of multiple conduit gripping devices or a ferrule set, we refer tothe out-board conduit gripping device (for example, the back ferrule30-4 in the embodiment of FIGS. 43-48) as the retaining conduit grippingdevice because in the exemplary embodiments herein the retainingstructure cooperates with the back ferrule 30-4. Alternative embodimentshowever may utilize a retaining structure that cooperates with the frontferrule 24-4 as the conduit gripping device.

The back ferrule 30-4 will coact with the second retaining portion 44-4,the latter of which will also coact with the retaining fitting component14-4, so as to retain the ferrule or ferrule set together with the nut14-4 as a discrete and discontinuous subassembly 25-4.

The second retaining portion 44-4 may be realized in the form of aretaining member such as a hook or clip-like device 46-4. The retainingmember 46-4 may be but does not necessarily have to be a generallyannular or ring-like structure that has a first portion 46 a-4 thatcatches or engages with a portion of the retaining fitting component ornut 14-4, and a second portion 46 b-4 that catches or engages with aportion of the back ferrule 30-4. In this embodiment, the retainingmember first portion 46 a-4 engages an outboard wall 14 a-4 of the nut14-4. The second portion 46 b-4 may include a reverse hook 48-4 that isreceived in the interior recess 39 a-4 of the back ferrule 30-4. Theretaining member 46-4 may compressively hold the back ferrule againstthe nut 14-4 drive wall 34-4, or there may be some looseness provided.Alternatively, the retaining member need not be a completely annularpart but may be a simple planar clip or a plurality of clips (not shown)that hold the back ferrule 30-4 with the nut 14-4. A third portion 46c-4 joins the first and second portions. The retaining member 46-4 mayhave some flex or give to it so that when the back ferrule 30-4 isinserted into the nut 14-4, the hook 48-4 may deflect radially outwardsomewhat to allow the back ferrule to be fully inserted into the nut andhave the hook 48-4 received in the interior recess 39 a-4.Alternatively, the retaining member 46-4 may be installed after theferrules have been inserted into the retaining fitting component 14-4.In the optional alternative case where the ferrule cartridge concept Ris also used, retention of the back ferrule 30-4 with the nut 14-4 alsoholds the front ferrule 24-4 as part of the cartridge assembly 25-4.

As with other embodiments above, the location, shape, size, length andprofile of the retaining member 46-4 will depend in part on the designof the cooperating first retaining portion 42-4 of the retaining conduitgripping device, in this case the back ferrule 30-4, as well as theshape of the retaining fitting component 14-4. The design of theretaining structure 40-4, including the design of the first retainingportion 42-4 and the second retaining portion 44-4, may also depend inpart on how robust a connection is desired between the retaining fittingcomponent and the conduit gripping devices, in other words, the natureof the retention force desired. For example, in some applications it maybe desired to have the ferrules 24-4, 30-4 strongly and securelyretained with the fitting component 14-4 so that the ferrules do notfall out or get knocked out during handling, shipping or exposure toother force applying environments, while in other applications such astrong retention force may not be needed. As another example, in someapplications it may be desired to have the ferrules snugly held togetherand retained with the fitting component, while in other applications itmay be more desirable to have the ferrules somewhat loosely heldtogether and retained with the fitting component. These are just a fewof the criteria that may be considered when designing the retainingstructure 40-4. The retaining member 46-4 may contact the back ferrule30-4 when the ferrules 24-4, 30-4 are installed in the retaining fittingcomponent, or may be axially spaced such that the retaining member onlycontacts the back ferrule 30-4 should the back ferrule drop down intocontact with the retaining member 46-4. Looser retention of the ferrulesin the nut 14-4 may facilitate pull-up of the fitting assembly by notinterfering with centering of the ferrules as the nut 14-4 is initiallyrotated relative to the body 12-4.

The second retaining portion 44-4 may be designed to achieve the desiredretaining force for the subassembly 25-4 prior to assembly with themating fitting component. The second retaining portion 44-4 may alsooptionally be designed to facilitate release of the retaining fittingcomponent from the one or more conduit gripping devices after assemblywith the mating fitting component, for example after or during a partialpull up or a complete pull up of the fitting assembly onto a conduit.

As in other embodiments herein, the retaining member 46-4, incooperation with the design of the interior recess 39 a of the backferrule, may also be designed such that the ferrules 24-4, 30-4 aresomewhat loosely retained and may even have a slight rattle when the nut14 is gently shaken. This looseness may in some applications facilitatefinal assembly with the second or mating fitting component (in thisexample the body 12-4), especially in allowing the ferrules to centerand align during pull-up of the fitting assembly 10-4. In alternativeembodiments, however, the ferrules 24-4, 30-4 may be snugly or eventightly retained in the nut 14-4.

The retaining conduit gripping device may have a retaining position anda release or disengage position. In the retaining position the conduitgripping devices and the retaining fitting component form and may beused as a discontinuous cartridge 25-4. In the release position, theretaining conduit gripping device is separable from the retainingstructure 40-4. Preferably, the retaining conduit gripping device is inthe release position after a partial or complete pull-up so as to notadversely interfere with the retaining fitting component.

The retaining member 46-4 may be made of any suitable material such asmetal or plastic, and preferably robust enough to retain the ferruleswith the nut 14-4 as a cartridge nut assembly 25-4. Use of a metalretaining member 46-4 allows for all metal fitting assemblies for hightemperature applications or use with fluids that may damage an elastomeror plastic. Suitable metals may include but are not limited to stainlesssteel, brass, copper, steel and so on to name just a few of the manyavailable materials.

FIGS. 43 and 44 show the subassembly 25-4 after it has been joined tothe second or mating fitting component 12-4 to a finger tight position.In this position, the retaining member 46-4 still has a hook 48-4disposed within the interior recess 39 a-4 of the back ferrule 30-4.With reference to FIG. 45, we show the body 12-4, the conduit grippingdevices 24-4,30-4, and the retaining fitting component or nut 14-4 afterthey have been tightened together during pull-up. In this example, weillustrate the parts tightened together after a complete pull-up. Duringpull-up, the ferrules 24-4 and 30-4 are axially compressed together byrelative axial movement between the nut 14-4 and the body 12-4. Thiscauses the ferrules to plastically deform so as to effect conduit gripand seal. For the exemplary fitting, the back ferrule deforms in such amanner that a rear portion 50-4 of the back ferrule rotates radiallyoutward from the conduit 18-4 as represented by the arrow Z in FIG. 45.This deformation is typically a plastic deformation but also maypartially include some elastic deformation. This rotation causes thehook 48 to be separated from the interior recess 39 a-4, therebyreleasing or separating the retaining member 46-4 from the back ferrule30-4. The retaining structure 40-4 preferably is designed so as to notinterfere with normal operation and pull-up of the conduit grippingdevices onto the conduit to effect grip and seal.

When the ferrule cartridge retaining structure R is also used, it willbe noted that the ferrules also release from each other during pull-up,because the front portion 28-4 of the back ferrule is radiallycompressed inward away from the retaining structure R1 of the frontferrule 24-4.

In an alternative embodiment, the retaining member 46-4, and especiallythe hook portion 48-4 may be elastic enough so that a back ferrule orsingle ferrule of different design may not need to be necessarilyplastically rotated away from the hook 48-4.

The design of the retaining member 46-4 may be chosen in concert withthe amount of relative axial displacement of the nut 14-4 and the body12-4 to determine at what point during pull-up the retaining member 46releases from the retaining conduit gripping device. For example, it maybe desired in some embodiments to have the retaining member 46-4released just prior to completion of a pull-up operation. As anotherexample, it may be desired to have the retaining member release after apartial pull-up or after a pre-swage operation.

Accordingly, one or more of the present inventions facilitates aretaining mechanism or structure and method by which one or moreferrules or conduit gripping devices may be retained with a fittingcomponent as a discontinuous cartridge 25-4, with the retainingstructure then being released by plastic deformation of the retainingconduit gripping device during pull-up (either a complete pull-up or apartial pull-up as needed) so that the nut 14-4 is released and maysubsequently be axially withdrawn or pulled back from the body 12-4.

For embodiments that use a retaining member 46-4 in the form of a clipor hook, it will be appreciated that in many uses the retaining member46-4 may be flexible but fairly stiff to provide a robust connectionbetween the conduit gripping devices and the retaining fittingcomponent. This stiffness may be used to assure a robust subassemblythat does not come apart too easily (as determined by the designer)during handling and shipping. It can therefore be expected that when theretaining member engages the retaining conduit gripping device (e.g. theback ferrule 30-4 as in the FIG. 43 embodiment), that the retainingmember 46-4 may snap into the interior recess 39 a-4 with sufficientimpact as to produce an audible “click”. This audible feedback may alertthe assembler directly that the retaining member has released, orsensors may be used (such as, for example, recorders, transmitters andlight indicators) to indicate sufficient pull-up to the releaseposition.

As noted above, use of the discontinuous cartridge 25-4 facilitatesproviding ferrule sets to the end user in which the ferrules and nutsare properly matched at the manufacturer. This can significantlysimplify inventory control and reduce final assembly time. Theembodiments herein also allow for a cartridge design in which theretaining fitting component may be used for fitting assemblies that donot need or have the retaining member 46-4. In other words, thecartridge designs herein use a nut or retaining fitting component thatis backwards compatible with fitting assemblies that the end user maynot require with a retaining structure. The cartridge design also may berealized using ferrule sets that do not require modification. Therefore,the cartridge concepts herein may be optionally provided for an end userwithout having to manufacture nuts or ferrules with different geometryand operation or performance. This allows the convenience ofmanufacturing and selling fitting components and ferrules as separateparts regardless of the end use of such individual parts, either for acartridge use or a non-cartridge use.

In an exemplary method, one or more conduit gripping devices areretained with a retaining fitting component as a discontinuouscartridge. This discontinuous cartridge forms a first part of a two partfitting assembly. The cartridge is then joined with the second part ofthe fitting assembly and a portion of a conduit. During at least apartial pull-up of the fitting assembly, the conduit gripping devicesbecome attached to the conduit and become disengaged from the retainingfitting component so that the retaining fitting component may be removedfrom the fitting assembly after the partial or complete pull-up whilethe one or more conduit gripping devices remain attached to the conduit.In a more specific embodiment, the method may include the steps ofretaining one or more conduit gripping devices with a retaining fittingcomponent as a discontinuous cartridge, joining the cartridge to asecond fitting component on a conduit to cause the conduit grippingdevices to attach to the conduit, and disengaging the retaining fittingcomponent from the conduit gripping devices so that the retainingfitting component may be removed from the fitting assembly after apartial pull-up while the one or more conduit gripping devices remainattached to the conduit. In still a more specific embodiment, theretaining member releases from the retaining conduit gripping device bydeformation of the retaining conduit gripping device during pull-up.

With reference to FIGS. 46-48, we illustrate another embodiment of aretaining member 70-4 that may be used to retain one or more conduitgripping devices with a retaining fitting component. In this example,the retaining member 70-4 may be realized in the form of a clip or tang72-4 that is integrally machined or formed as an extension of aninterior wall 74-4 of the nut 14-4. This tang 72-4 may alternatively beattached to the nut by any suitable process such as welding. The tang72-4 may be dimensioned so as to have a surface 72 a-4 that provides adesired friction fit with a back end wall portion 76-4 of the backferrule 30-4 so as to hold onto the back ferrule. The optional ferrulecartridge retaining feature R may also be used for two ferrule fittings.During pull-up, the back ferrule 30-4 deforms in such a manner that therear portion 78-4 of the back ferrule rotates radially outward from theconduit 18-4 as represented by the arrow Z in FIG. 48. This rotationcauses the tang 72-4 to be separated from the back ferrule back end wallportion 76-4, thereby releasing or separating the retaining member 70-4from the back ferrule 30-4. The release or separation of the tangsurface 72 a-4 from the back ferrule back end wall portion 76-4 may butneed not be accompanied by the two surfaces being out of contact afterpull-up. In some applications it may be sufficient that the back ferruledeform only to such an extent as to remove or substantially reduce thefrictional engagement between the surfaces. The retaining member 70-4preferably is designed so as to not interfere with normal operation andpull-up of the conduit gripping devices onto the conduit to effect gripand seal.

In further alternative embodiments, a single ferrule or the ferrulecartridge retaining structure R may be used with an adhesive or otherattachment means applied to a back or outboard end of the back ferrule30-4 to hold the conduit gripping devices with the retaining fittingcomponent as a cartridge nut. In another alternative, spot welding maybe used to secure a back or outboard end of the back ferrule 30-4 tohold the conduit gripping devices with the retaining fitting componentas a cartridge nut. For fittings that use silver plating or otherlubricant on the retaining fitting component, this plating may beremoved prior to the spot welding operation. Autogenous spot welding maybe conveniently used between the back end of the back ferrule and aninner surface of the nut 14-4.

FIG. 49 illustrates in partial longitudinal cross-section an embodimentof a cartridge nut concept that uses welded parts. The body 12-4 (notshown), nut 14-4 and cartridge ferrules 24-4, 30-4 may be similar tothose described hereinabove and like reference numerals are used forlike parts. In this example, a rearward surface 80-4 of the back ferrule30-4 may be tack welded as at 82-4 to an interior surface 84-4 of thenut 14-4. The location of the tack weld 82-4 may be chosen as convenientfor the welding process to be used. More than one tack weld may be used,and the size of the weld 82-4 may be selected to achieve the desiredrobustness for the cartridge nut, yet able to fracture or break duringpull-up of the fitting. Preferably, the weld will not break duringassembly to the finger-tight position as shown in FIG. 49, but uponrelative rotation of the nut and body will break so as to disengage theback ferrule 30-4 from the nut 14-4 so as not to interfere with thenormal pull-up performance of the fitting.

Although the adhesive and welding embodiments are not discontinuouscartridge embodiments per se, they may be useful in some fitting designsas the fitting components require no modification from their originaldesign.

The inventive aspects have been described with reference to theexemplary embodiments. Modification and alterations will occur to othersupon a reading and understanding of this specification. It is intendedto include all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof

We claim:
 1. A fitting subassembly comprising: a threaded fitting nutthat can be joined with a threaded fitting body to form a fittingassembly, the fitting nut including a radial drive surface and aninterior wall defining a socket; and a back ferrule disposed entirely inthe socket and including a driven surface adjacent to the drive surface;a front ferrule at least partially disposed in the socket; and aretaining member that retains said front ferrule and said back ferrulewith said fitting nut as a subassembly prior to said fitting nut beingassembled with a threaded fitting body; wherein the retaining memberapplies a retaining force that is limited to permit removal of the frontferrule and the back ferrule from the fitting nut by exposure to a forceapplying environment; wherein the retaining member retains said frontferrule and said back ferrule with said fitting nut when the retainingmember is in a first position prior to said fitting nut being assembledwith said fitting body, the retaining member being movable to a secondposition within the fitting nut to release the front ferrule and theback ferrule from the fitting nut; and wherein the retaining member isradially movable from the first position to the second position.
 2. Thefitting subassembly of claim 1, wherein the fitting nut comprises afemale threaded fitting nut.
 3. The fitting subassembly of claim 1,wherein the retaining member is flexible to permit removal of the frontferrule and the back ferrule from the fitting nut.
 4. The fittingsubassembly of claim 1, wherein the retaining member comprises anannular ring, separate from and retained within the fitting nut.
 5. Thefitting subassembly of claim 1, wherein the retaining member is movedfrom the first position to the second position when the fitting nut isassembled with a fitting body.
 6. The fitting subassembly of claim 1,wherein the retaining member is axially movable from the first positionto the second position.
 7. The fitting subassembly of claim 1, whereinthe retaining member is bendable from the first position to the secondposition.
 8. The fitting subassembly of claim 1, wherein the retainingmember is radially compressible from the first position to the secondposition.
 9. The fitting subassembly of claim 1, wherein the retainingmember is separate from and retained in a recess in the fitting nut. 10.The fitting subassembly of claim 1, wherein the retaining member isseparate from and retained in a recess in the front ferrule.
 11. Thefitting subassembly of claim 1, wherein the fitting subassemblycomprises only metal parts.
 12. A fitting assembly for conduits,comprising: a threaded first fitting component to be assembled with athreaded second fitting component, to provide an interior volume, afront ferrule and a back ferrule both disposed entirely in said interiorvolume, said second fitting component comprising a drive surface thatengages a back wall of said back ferrule when the fitting assembly ispulled-up, a retaining member that retains said front ferrule and saidback ferrule with said second fitting component as a subassembly priorto said first fitting component being assembled with said second fittingcomponent, wherein the retaining member applies a retaining force thatpermits removal of the front ferrule and the back ferrule from thesecond fitting component by exposure to a force applying environment,and wherein the retaining member retains said front ferrule and saidback ferrule with said second fitting component when the retainingmember is in a first position prior to said second fitting componentbeing assembled with said first fitting component, the retaining memberbeing movable to a second position within the second fitting componentto release the front ferrule and the back ferrule from the secondfitting component.
 13. The fitting assembly of claim 12, wherein thefirst fitting component comprises a male threaded fitting body and thesecond fitting component comprises a female threaded fitting nut.
 14. Afitting subassembly comprising: a first fitting component that can bejoined to a second fitting component to make a threaded fittingassembly, the first fitting component including an interior walldefining a socket; at least one conduit gripping device disposed withinthe socket; and a retaining member, separate from and assembled with thefirst fitting component to retain said at least one conduit grippingdevice with the first fitting component; wherein the retaining member ismovable with respect to said first fitting component from a firstposition in which said at least one conduit gripping device is retainedwith said first fitting component, to a second position in which said atleast one conduit gripping device becomes separable from said firstfitting component.
 15. The fitting subassembly of claim 14, wherein theretaining member applies a retaining force sufficient to securely retainthe at least one conduit gripping device with the body so that the atleast one conduit gripping device does not fall out or get knocked outof the body during handling, shipping or exposure to other forceapplying environments.
 16. The fitting subassembly of claim 14, whereinthe retaining member applies a retaining force that permits removal ofthe at least one conduit gripping device from the first fittingcomponent by exposure to a force applying environment.